Big Dig "Ginsu guardrails"

Post by John F. Carr
Several people have died after being dismembered by pedestrian
handrails in the Big Dig tunnels, according to the Boston Globe.

<http://www.boston.com/news/local/massachusetts/articles/2010/02/14/th...>
--

Three out of seven of the accidents involved cars going at least twice
the speed limit (one going 100mph in a 25 zone) and apparently two of
those were not wearing seat belts while the other occupants who
suffered minor injuries did wear seat belts.Two of the other accidents
involved motorcycles who were inexpierenced drivers going over the
speed limit. I don't know if you can design something to protect
people from every possible hazard they expose themselves to.

Elmer

2010-02-14 15:35:25 UTC

Post by Route2 driver

Post by John F. Carr
Several people have died after being dismembered by pedestrian
handrails in the Big Dig tunnels, according to the Boston Globe.

<http://www.boston.com/news/local/massachusetts/articles/2010/02/14/th...>
--

The State policeman on the motorcycle, who was being followed by
another State police car was neither inexperienced nor speeding. The
curve where his accident occurred is particularly dangerous.
Regardless, the design of the handrails contributed to his injuries in
ways that with standard (i.e. previously tested) handrails would have
been much less likely to occur. There was no need to use this custom
design. It added no value to the project; even the manufacturer
suggested a less expensive, proven alternative. Yet, someone in charge
at the time insisted upon their fancy (i.e. expensive) design.

Elmer

unknown

2010-02-14 18:39:37 UTC

Post by Route2 driver

Post by John F. Carr
Several people have died after being dismembered by pedestrian
handrails in the Big Dig tunnels, according to the Boston Globe.

<http://www.boston.com/news/local/massachusetts/articles/2010/02/14/th...>
--

As many die wearing seat belts as those that don't.
Wearing a seat belt would not have stopped the impaling or slicing by
the railing.

Elmer

2010-02-14 15:17:25 UTC

Post by John F. Carr
Several people have died after being dismembered by pedestrian
handrails in the Big Dig tunnels, according to the Boston Globe.

<http://www.boston.com/news/local/massachusetts/articles/2010/02/14/th...>
--

Reading that Globe article today made me very sad. I've always looked
with disdain at those railings, primarily because I saw them as a huge
waste of money. Instead of using cheaper, industry standard railings,
perhaps made of a less-expensive steel, I thought it was pretty stupid
to make fancy railings that, because of their location, were only
destined to be smashed by vehicles anyway! Many sections are now
missing altogether, which as I read today is actually for the better.

I believe the reason for the railings is because consulting companies
like Parsons-Brinkerhoff are paid based on the cost of the
construction and fixtures they specify. They make even more money by
creating their own custom designs, rather than using off-the-shelf
fixtures. In addition to needlessly escalating the initial cost of a
project, it creates a legacy of huge maintenance costs into the future
because replacement parts for the custom designs are expensive if not
impossible to obtain. More often, the expensive fixtures receive
little if any maintenance and become useless to their original
purpose. So, why else spend the extra money to specify them in the
first place?

This "culture" was/is not limited to the Big Dig. Take a look anywhere
on the MBTA and you'll find custom specified designs that cost much
more than off-the-shelf hardware that could do the same thing cheaper
and usually better. Start with, for example, light fixtures. That's
something everyone can see. Next time you're in a T station, compare
the light fixtures with what you'd see a "normal" commercial location
like a shopping mall. If you continue the shopping mall comparison
with other aspects of station design, you'll see many examples of what
I'm talking about. The DCR just "proudly" installed new fancy green
(i.e. expensive) guardrails on Storrow Drive. They've already been hit
and damaged. If they really wanted the road to look nice, just buy
inexpensive guard rail (light fixtures, etc.), but be meticulous about
maintaining it.

Please don't forget Mrs. DelValle who was killed when the glue holding
a concrete ceiling panel failed. It was subsequently determined that
no panels at all were ever needed in that part of the tunnel and
ultimately the panels and their fatally designed framework had to be
completely removed.

Elmer

Another quote form The Globe article:
http://www.boston.com/news/local/massachusetts/articles/2010/02/14/the_big_digs_deadly_safety_rails/?page=3

" A design using a cylindrical post handrail has been part of the
MassHighway design specifications for more than 40 years, according to
documents in the case file, and is used in the Sumner and Callahan
tunnels, for example. In New York, the Lincoln Tunnel uses a pipe-
style handrailing that starts about 4 feet off the road, said a
spokeswoman.

Big Dig managers could have used a rounded pipe design for handrails
in that system, too. In 1999, the manufacturer of the handrails tried
to convince the Massachusetts Turnpike and Bechtel/Parsons
Brinckerhoff, which managed the project, that rounded vertical
railings were the way to go.

Switching to the cylindrical pipe designs could have saved between
nearly $300,000 to more than $700,000, Tuttle, the railing
manufacturer, said in a 1999 memo. Officials at Modern agreed and
fought for the change, according to Big Dig documents in the suit.

But for reasons that are not clear in the court documents, officials
at Bechtel/Parsons Brinckerhoff did not agree. The original design,
with the edges, was used. "

John Lansford

2010-02-14 18:40:21 UTC

Post by John F. Carr
Several people have died after being dismembered by pedestrian
handrails in the Big Dig tunnels, according to the Boston Globe.

<http://www.boston.com/news/local/massachusetts/articles/2010/02/14/the_big_digs_deadly_safety_rails/>

First off, any motorcyclist hitting any highway guardrail design is
going to suffer severe injuries. Guardrails are designed to redirect
or stop 2 ton vehicles travelling at high speeds; a human body
striking any part of a steel barrier is going to get hurt, and hurt
very badly.

Similarly, anyone thrown from a car and hitting a guardrail barrier is
going to get hurt badly for the same reason. It's why everyone should
wear seat belts; your chance of survival is much higher if you stay in
the car and let the vehicle's structure take the damage instead of
you.

Third, here's a little secret very few non-highway engineers know;
there are VERY few lateral highway barriers in use in the US that were
designed for speeds higher than 55mph. That video linked to the Globe
article? Those crashes appeared to be around 45-50mph at the sharpest
expected angle from standard highway maneuvers. The test vehicles are
also standard sedans and pickup trucks; oh, you're driving a 3 ton
SUV? Sorry, the guardrail isn't designed to redirect your vehicle and
in fact, you'll probably roll right over the top of it. No DOT will
tell you that if you strike the standard steel beam guardrail at 80mph
that you'll be safely redirected from the obstacle it's trying to keep
you from hitting. In fact, they don't even know what will happen if
you hit guardrail at that speed. You might bounce off, you might go
airborne, you might burst right through it, or your car might just
disintegrate.

Fourth, calling the guardrail "ginsu like" is misleading since so many
of the deaths were motorcyclists (see above) or were travelling at
extreme high speeds. A rounded post probably wouldn't "cut" your arm
off, but if you hit it at 50mph the resulting trauma would probably
just rip it off anyway. Again, steel lateral barriers are NOT
designed to avoid human body injuries while at the same time
performing their primary function of redirecting big metal vehicles.

Does anyone have a photo of the railings in question, BTW? The
article didn't show what they looked like.
--
John's Shop of Wood
http://wood.jlansford.net/

Andrew M. Saucci, Jr.

2010-02-14 20:19:31 UTC

As I often say, maybe the road is designed for 75 mph, but your body
ISN'T!

Post by John F. Carr
Several people have died after being dismembered by pedestrian
handrails in the Big Dig tunnels, according to the Boston Globe.

<http://www.boston.com/news/local/massachusetts/articles/2010/02/14/the_big_digs_deadly_safety_rails/>

First off, any motorcyclist hitting any highway guardrail design is
going to suffer severe injuries. Guardrails are designed to redirect
or stop 2 ton vehicles travelling at high speeds; a human body
striking any part of a steel barrier is going to get hurt, and hurt
very badly.
Similarly, anyone thrown from a car and hitting a guardrail barrier is
going to get hurt badly for the same reason. It's why everyone should
wear seat belts; your chance of survival is much higher if you stay in
the car and let the vehicle's structure take the damage instead of
you.
Third, here's a little secret very few non-highway engineers know;
there are VERY few lateral highway barriers in use in the US that were
designed for speeds higher than 55mph. That video linked to the Globe
article? Those crashes appeared to be around 45-50mph at the sharpest
expected angle from standard highway maneuvers. The test vehicles are
also standard sedans and pickup trucks; oh, you're driving a 3 ton
SUV? Sorry, the guardrail isn't designed to redirect your vehicle and
in fact, you'll probably roll right over the top of it. No DOT will
tell you that if you strike the standard steel beam guardrail at 80mph
that you'll be safely redirected from the obstacle it's trying to keep
you from hitting. In fact, they don't even know what will happen if
you hit guardrail at that speed. You might bounce off, you might go
airborne, you might burst right through it, or your car might just
disintegrate.
Fourth, calling the guardrail "ginsu like" is misleading since so many
of the deaths were motorcyclists (see above) or were travelling at
extreme high speeds. A rounded post probably wouldn't "cut" your arm
off, but if you hit it at 50mph the resulting trauma would probably
just rip it off anyway. Again, steel lateral barriers are NOT
designed to avoid human body injuries while at the same time
performing their primary function of redirecting big metal vehicles.
Does anyone have a photo of the railings in question, BTW? The
article didn't show what they looked like.
--
John's Shop of Wood
http://wood.jlansford.net/

Elmer

2010-02-15 01:58:10 UTC

As I often say, maybe the road is designed for 75 mph, but your body
ISN'T!

That is certainly true. It was also said the Chevrolet Corvair was
unsafe at any speed.

Elmer

Elmer

2010-02-15 01:54:50 UTC

Post by John F. Carr
Several people have died after being dismembered by pedestrian
handrails in the Big Dig tunnels, according to the Boston Globe.

<http://www.boston.com/news/local/massachusetts/articles/2010/02/14/th...>

First off, any motorcyclist hitting any highway guardrail design is
going to suffer severe injuries. Guardrails are designed to redirect
or stop 2 ton vehicles travelling at high speeds; a human body
striking any part of a steel barrier is going to get hurt, and hurt
very badly.
Similarly, anyone thrown from a car and hitting a guardrail barrier is
going to get hurt badly for the same reason. It's why everyone should
wear seat belts; your chance of survival is much higher if you stay in
the car and let the vehicle's structure take the damage instead of
you.
Third, here's a little secret very few non-highway engineers know;
there are VERY few lateral highway barriers in use in the US that were
designed for speeds higher than 55mph. That video linked to the Globe
article? Those crashes appeared to be around 45-50mph at the sharpest
expected angle from standard highway maneuvers. The test vehicles are
also standard sedans and pickup trucks; oh, you're driving a 3 ton
SUV? Sorry, the guardrail isn't designed to redirect your vehicle and
in fact, you'll probably roll right over the top of it. No DOT will
tell you that if you strike the standard steel beam guardrail at 80mph
that you'll be safely redirected from the obstacle it's trying to keep
you from hitting. In fact, they don't even know what will happen if
you hit guardrail at that speed. You might bounce off, you might go
airborne, you might burst right through it, or your car might just
disintegrate.
Fourth, calling the guardrail "ginsu like" is misleading since so many
of the deaths were motorcyclists (see above) or were travelling at
extreme high speeds. A rounded post probably wouldn't "cut" your arm
off, but if you hit it at 50mph the resulting trauma would probably
just rip it off anyway. Again, steel lateral barriers are NOT
designed to avoid human body injuries while at the same time
performing their primary function of redirecting big metal vehicles.
Does anyone have a photo of the railings in question, BTW? The
article didn't show what they looked like.
--
John's Shop of Woodhttp://wood.jlansford.net/

John, these are not guard rails, they are hand rails mounted on top of
New Jersey style barriers at the edges of the roadway. The handrails
aren't everywhere, and are usually only on one side of the road.
Unfortunately, the Jersey barriers are too short. So, instead of doing
their designed job of gently diverting off-course vehicles back on the
road, they're just pushing them up to be caught on the deadly
handrails. Before some of the above ground ramps were opened (e.g.:
Leverett Connector, Tobin loops), it was discovered that their Jersey
barriers were too short to meet Federal standards. They were
subsequently retrofitted with additional metal guard rails on top of
the concrete barriers. This is completely different from the handrails
on top of the barriers inside the tunnels.

In the videos below, the handrails are visible in the first beginning
at 1:20 and in the second video at 3:00:

John Lansford

2010-02-15 10:04:30 UTC

Post by Elmer
John, these are not guard rails, they are hand rails mounted on top of
New Jersey style barriers at the edges of the roadway. The handrails
aren't everywhere, and are usually only on one side of the road.
Unfortunately, the Jersey barriers are too short. So, instead of doing
their designed job of gently diverting off-course vehicles back on the
road, they're just pushing them up to be caught on the deadly
Leverett Connector, Tobin loops), it was discovered that their Jersey
barriers were too short to meet Federal standards. They were
subsequently retrofitted with additional metal guard rails on top of
the concrete barriers. This is completely different from the handrails
on top of the barriers inside the tunnels.
In the videos below, the handrails are visible in the first beginning
http://youtu.be/iBw2c5FtvS8
http://youtu.be/VnUocYpKIY4

The 32" high Jersey Barrier works everywhere else; why is it
considered substandard here? ISTM that the higher speeds of several
of those crashes is more at fault here than a defect in the barrier.
Again, anyone thrown even partially out of a vehicle in a crash is
going to be severely injured or killed if they hit a barrier. Jersey
Barriers are designed to keep vehicles from reaching the top of the
barrier when struck at designed speeds.

John Lansford, PE
--
John's Shop of Wood
http://wood.jlansford.net/

Elmer

2010-02-15 13:27:59 UTC

Post by John Lansford
The 32" high Jersey Barrier works everywhere else; why is it
considered substandard here? ISTM that the higher speeds of several
of those crashes is more at fault here than a defect in the barrier.
Again, anyone thrown even partially out of a vehicle in a crash is
going to be severely injured or killed if they hit a barrier. Jersey
Barriers are designed to keep vehicles from reaching the top of the
barrier when struck at designed speeds.

The concrete barriers (e.g.: on the elevated ramps of the Leverett
Connector) were not built to the Federal standard. That's why they had
to be retrofitted with additional metal guard rails. I don't know
whether or not the concrete barriers within the tunnels had to meet
the same standard.

May I point out that speeding, errant drivers aren't the only ones who
depend on safely designed barriers. Frequently, innocent drivers are
hit by other vehicles and driven into the walls. If that happened to
you, would you want an arm ripped off because some consultant insisted
upon their fancy expensive handrail design?

Elmer

H.B. Elkins

2010-02-15 14:16:18 UTC

Have design standards changed for Jersey barriers? The barrier on the common
section of I-64 and I-75 around Lexington, Ky., which was expanded to six lanes
in the 1980s, is considerably shorter than the median barrier for newer sections
of six-lane interstate to the north, east and south of the common section.

--
To reply by e-mail, remove the "restrictor plate"

John F. Carr

2010-02-15 14:49:45 UTC

Post by H.B. Elkins
Have design standards changed for Jersey barriers? The barrier on the common
section of I-64 and I-75 around Lexington, Ky., which was expanded to six lanes
in the 1980s, is considerably shorter than the median barrier for newer sections
of six-lane interstate to the north, east and south of the common section.

The Massachusetts Turnpike Authority has been using higher barriers
for a decade or more to better handle SUVs and small trucks. The
higher barriers may be a national standard.

--
John Carr (***@mit.edu)

Elmer

2010-02-15 17:32:39 UTC

Post by John F. Carr

The Massachusetts Turnpike Authority has been using higher barriers
for a decade or more to better handle SUVs and small trucks. The
higher barriers may be a national standard.
--

The height and also the curvature geometry of the standard "New
Jersey" style concrete barrier has evolved over the years, based on
studies of their effectiveness. I've also noticed (e.g.: recently in
Massachusetts on I-495) that plain old steel guardrails are now being
mounted higher than before.

On the Big Dig ramps I mentioned though, whoever was charged with
ensuring the construction met current standards failed to do their
job. Only just before the road was opened did (Federal?) inspections
reveal the barriers were substandard and had to be "redesigned".

Elmer

John Lansford

2010-02-15 22:47:41 UTC

Post by John F. Carr

The Massachusetts Turnpike Authority has been using higher barriers
for a decade or more to better handle SUVs and small trucks. The
higher barriers may be a national standard.
--

Or perhaps the steel beam guardrail wasn't located at the proper
height in the first place. Federal guidelines for height placement of
steel guardrail is very specific to avoid vehicles 'submarining' under
it. There are all sorts of concrete barrier shapes that meet Federal
crash tests, though.

John Lansford, PE
--
John's Shop of Wood
http://wood.jlansford.net/

John Lansford

2010-02-15 22:44:34 UTC

Post by H.B. Elkins

There have been some slight changes to the original shape that
enhances its redirection capability, but they are fairly minor. I
think there's a small vertical section at the base, and a more
vertical upper portion, but there's all sorts of FHWA approved shapes
that meet their crash test requirements.

There's a higher barrier that has been approved that's about 54" high
that has an elongated Jersey shape and performs a glare screen
function as well as redirection, and there's a medium height barrier
that's about 42" high when the % of trucks is low enough that glare
from them isn't an issue. The standard is still about 32" high
though.

John Lansford, PE
--
John's Shop of Wood
http://wood.jlansford.net/

Jonathan L

2010-02-16 08:39:06 UTC

Post by H.B. Elkins

There have been some slight changes to the original shape that
enhances its redirection capability, but they are fairly minor. I
think there's a small vertical section at the base, and a more
vertical upper portion, but there's all sorts of FHWA approved shapes
that meet their crash test requirements.
There's a higher barrier that has been approved that's about 54" high
that has an elongated Jersey shape and performs a glare screen
function as well as redirection, and there's a medium height barrier
that's about 42" high when the % of trucks is low enough that glare
from them isn't an issue. The standard is still about 32" high
though.
John Lansford, PE
--
John's Shop of Woodhttp://wood.jlansford.net/

Is there a recommended height for barriers that's higher than the
standard? Just curious. WSDOT seems to have abandoned the Jersey
barrier in favor the constant-slope barrier style. Even on non-
freeway state highways, when barriers are installed they're always
constant-slope and have guardrail on top when on the side of the
road. I've always wondered if it was because there's not an approved
Jersey barrier type that's tall enough.

-Jonathan

John Lansford

2010-02-16 10:35:24 UTC

Post by Jonathan L

Post by H.B. Elkins

There have been some slight changes to the original shape that
enhances its redirection capability, but they are fairly minor. I
think there's a small vertical section at the base, and a more
vertical upper portion, but there's all sorts of FHWA approved shapes
that meet their crash test requirements.
There's a higher barrier that has been approved that's about 54" high
that has an elongated Jersey shape and performs a glare screen
function as well as redirection, and there's a medium height barrier
that's about 42" high when the % of trucks is low enough that glare
from them isn't an issue. The standard is still about 32" high
though.

I guess it depends on what you mean by "standard height". The nominal
height for a Jersey barrier is 32". That's the height of the ones you
see on older highway barriers, or temporary concrete barriers. Most
states are going with a higher one because the 32" height doesn't
prevent a semi from rolling over it after an impact. The 42" and 54"
barriers work better to prevent rollovers. Like I said, there's all
sorts of shapes approved by FHWA, so as long as they work the states
are free to select a shape they prefer.

John Lansford, PE
--
John's Shop of Wood
http://wood.jlansford.net/

Larry G

2010-02-16 00:14:08 UTC

Post by John F. Carr
Several people have died after being dismembered by pedestrian
handrails in the Big Dig tunnels, according to the Boston Globe.

<http://www.boston.com/news/local/massachusetts/articles/2010/02/14/th...>

sort of off-topic... so if I need to start a new topic.. let me know

does anyone know of any implementation of the NASCAR-style SAFER
barriers anywhere on a public road?

Andrew Tompkins

2010-02-16 03:49:56 UTC

Post by John F. Carr
Several people have died after being dismembered by pedestrian
handrails in the Big Dig tunnels, according to the Boston Globe.

<http://www.boston.com/news/local/massachusetts/articles/2010/02/14/th...>

sort of off-topic... so if I need to start a new topic.. let me know
does anyone know of any implementation of the NASCAR-style SAFER
barriers anywhere on a public road?

Probably way too cost prohibitive. Considering that very few people on
the open road are going to be hitting it at 150+ MPH, you wouldn't be
getting much out of it that ordinary guardrail, guiderail and jersey
barrier don't already provide.

--Andy

Larry G

2010-02-16 10:53:53 UTC

Post by John F. Carr
Several people have died after being dismembered by pedestrian
handrails in the Big Dig tunnels, according to the Boston Globe.

<http://www.boston.com/news/local/massachusetts/articles/2010/02/14/th...>

sort of off-topic... so if I need to start a new topic.. let me know
does anyone know of any implementation of the NASCAR-style SAFER
barriers anywhere on a public road?

well.. I'm sure the design itself could be altered to deal with
different speeds and crash forces.... but what prompted the question
was, in part, John's comment that the current standard is only
55.... other than that.. I admit, I have no clue about the cost per
foot comparison or the design issues.

Elmer

2010-02-16 14:08:21 UTC

Post by John F. Carr
Several people have died after being dismembered by pedestrian
handrails in the Big Dig tunnels, according to the Boston Globe.

<http://www.boston.com/news/local/massachusetts/articles/2010/02/14/th...>

sort of off-topic... so if I need to start a new topic.. let me know
does anyone know of any implementation of the NASCAR-style SAFER
barriers anywhere on a public road?

This reminds me of a type of median barrier that was tried on a
stretch of I-95 between Miami and Ft. Lauderdale in the 1980's. Prior
to this time, there was just a grassy swale between what was then, a
mere three lanes in either direction. The inevitable deadly head-on
collisions were taking a huge toll. This was still a few years before
the first major rebuilding and widening of I-95 that coincided with
the initial construction of I-595.

The State decided to install a median barrier in the center of I-95,
but try a couple of different technologies to see which worked best,
so that what was learned could be applied to designs in the upcoming
projects. Typical New Jersey style barrier was used in some sections,
but this was the first time I saw it being slip-cast in place;
extruded like toothpaste from a cool little machine that followed a
precisely placed wire down the road. It seemed like a nice system at
the time. (and still is for many things; the machines use different
attachments to efficiently extrude curbing and other high quality
concrete slip-castings)

But also, through the Hallandale - Hollywood area, the State tested a
completely different design. It was about the same height as a Jersey
barrier, but it was 2-3 feet wide and made of made of steel. The
interior was filled with sand. Studies showed that the sand-filled
steel design was cheaper to install and maintain than a concrete
median barrier, absorbed the impact of a crash better, and was more
effective at redirecting vehicles in a safer direction. The only
problem was, it was not made of concrete. (Florida's cement industry
had (still has?) very powerful lobbyists in Tallahassee.)

Elmer

Otto Yamamoto

2010-02-16 18:03:00 UTC

Post by Elmer
But also, through the Hallandale - Hollywood area, the State tested a
completely different design. It was about the same height as a Jersey
barrier, but it was 2-3 feet wide and made of made of steel. The
interior was filled with sand. Studies showed that the sand-filled steel
design was cheaper to install and maintain than a concrete median
barrier, absorbed the impact of a crash better, and was more effective
at redirecting vehicles in a safer direction. The only problem was, it
was not made of concrete.

This sort of barrier was also used along the PA Turnpike and may still be
in place between Harrisburg and Breezewood. I believe it's the
International Barrier Corporation's Mark VII barrier. Here's a 1992
Virginia Transportation Research Council report that gives some detail on
an experimental installation:
http://tinyurl.com/yft24yh

and a 1990 Iowa DOT evaluation:
http://tinyurl.com/ya4qs5r

it's also listed in http://tinyurl.com/yk8upsl (FWHA Roadway Departure
Safety section), but there's no documentation available. There's also a
Mark IX concrete barrier(also sand filled)

The VTRC report notes that the barrier cost double what a concrete
barrier installation; the Iowa DOT report notes the cost as nearly 4
times the cost of a standard jersey wall(130 per linear foot vs $23.50),
and also noted a lack of available spare panels. Both reports note that
the barrier, once installed, required virtually no maintenance, however,
no serious accidents occurred in the evaluation period at either site, so
actual durability couldn't be conclusively determined.

I also seem to recall reading about it in either Popular Science or
Popular Mechanics(I Googled to no avail) in the mid 90's-it was heralded
as the 'next big thing' in central reservation barriers.

--
Otto Yamamoto

Elmer

2010-02-16 21:39:36 UTC

This sort of barrier was also used along the PA Turnpike and may still be
in place between Harrisburg and Breezewood. I believe it's the
International Barrier Corporation's Mark VII barrier. Here's a 1992
Virginia Transportation Research Council report that gives some detail on
an experimental installation:http://tinyurl.com/yft24yh
and a 1990 Iowa DOT evaluation:http://tinyurl.com/ya4qs5r
it's also listed inhttp://tinyurl.com/yk8upsl(FWHA Roadway Departure
Safety section), but there's no documentation available. There's also a
Mark IX concrete barrier(also sand filled)
The VTRC report notes that the barrier cost double what a concrete
barrier installation; the Iowa DOT report notes the cost as nearly 4
times the cost of a standard jersey wall(130 per linear foot vs $23.50),
and also noted a lack of available spare panels. Both reports note that
the barrier, once installed, required virtually no maintenance, however,
no serious accidents occurred in the evaluation period at either site, so
actual durability couldn't be conclusively determined.
I also seem to recall reading about it in either Popular Science or
Popular Mechanics(I Googled to no avail) in the mid 90's-it was heralded
as the 'next big thing' in central reservation barriers.
--
Otto Yamamoto

Yes, you're exactly right. The very section of I-95 in Florida I was
thinking of is written about in the Virginia report. According to that
report, the initial cost there was 37% more than a concrete barrier.
Though the sand-filled steel barrier appeared to be much safer (zero
rollover accidents vs. 12 rollover accidents with concrete), the
safety benefits and maintenance costs were apparently not considered
in the ultimate decision which allowed concrete barriers to compete
equally in bids for future construction projects.

I remember reading a newspaper article at the time (Miami Herald or
Ft. Lauderdale Sun Sentinal) that criticized the state for caving in
to the cement lobbyists instead of using the safer design. Their
figures included anticipated maintenance, which showed the sand-steel
barriers to be quite a bit less expensive than concrete.

Elmer

John Lansford

2010-02-16 22:39:13 UTC

Post by John F. Carr
Several people have died after being dismembered by pedestrian
handrails in the Big Dig tunnels, according to the Boston Globe.

<http://www.boston.com/news/local/massachusetts/articles/2010/02/14/th...>

sort of off-topic... so if I need to start a new topic.. let me know
does anyone know of any implementation of the NASCAR-style SAFER
barriers anywhere on a public road?

This reminds me of a type of median barrier that was tried on a
stretch of I-95 between Miami and Ft. Lauderdale in the 1980's. Prior
to this time, there was just a grassy swale between what was then, a
mere three lanes in either direction. The inevitable deadly head-on
collisions were taking a huge toll. This was still a few years before
the first major rebuilding and widening of I-95 that coincided with
the initial construction of I-595.
The State decided to install a median barrier in the center of I-95,
but try a couple of different technologies to see which worked best,
so that what was learned could be applied to designs in the upcoming
projects. Typical New Jersey style barrier was used in some sections,
but this was the first time I saw it being slip-cast in place;
extruded like toothpaste from a cool little machine that followed a
precisely placed wire down the road. It seemed like a nice system at
the time. (and still is for many things; the machines use different
attachments to efficiently extrude curbing and other high quality
concrete slip-castings)
But also, through the Hallandale - Hollywood area, the State tested a
completely different design. It was about the same height as a Jersey
barrier, but it was 2-3 feet wide and made of made of steel. The
interior was filled with sand. Studies showed that the sand-filled
steel design was cheaper to install and maintain than a concrete
median barrier, absorbed the impact of a crash better, and was more
effective at redirecting vehicles in a safer direction. The only
problem was, it was not made of concrete. (Florida's cement industry
had (still has?) very powerful lobbyists in Tallahassee.)

Sand filled crash barriers work great as long as the sand doesn't get
washed out, or in cold areas, gets wet and freezes. However, once
they're struck, they require immediate maintenance to restore their
capability, and then there's the routine maintenance to make sure the
sand remains a particular density and doesn't settle.

Probably why they haven't become very popular.

I do wonder how FlDOT expected to test these different barriers. Did
they ask motorists to deliberately run into each type? FHWA performs
crash tests with similar weight vehicles at similar crash angles and
speeds to determine performances. No way could "live fire" tests
generate the same kind of performance data.

John Lansford, PE
--
John's Shop of Wood
http://wood.jlansford.net/

Otto Yamamoto

2010-02-17 00:45:32 UTC

Post by John Lansford
Sand filled crash barriers work great as long as the sand doesn't get
washed out, or in cold areas, gets wet and freezes.

Both the Iowa and Virgina reports said the barriers required no
maintenance. If the sand became wet or froze, then you'd have a more
rigid barrier equivalent to a concrete barrier, anyway, wouldn't you?

Post by John Lansford
However, once they're struck, they require immediate maintenance to
restore their capability, and then there's the routine maintenance to
make sure the sand remains a particular density and doesn't settle.

In the Iowa report, that concern was noted, as well as a lack of spare
panels. They also note the panels were drilled for a straight
installation, whereas their installation was on curved slip roads.

Post by John Lansford
Probably why they haven't become very popular.

I think it was an idea with merit, but International Barrier Corporation
didn't have enough resources to really push it. I don't know if they even
exist any more, since I couldn't find a result on Google.

Post by John Lansford
I do wonder how FlDOT expected to test these different barriers. Did
they ask motorists to deliberately run into each type? FHWA performs
crash tests with similar weight vehicles at similar crash angles and
speeds to determine performances. No way could "live fire" tests
generate the same kind of performance data.

And there's a major issue. There were no data on how this barrier would
perform under severe circumstances. Would you take a risk on something
like that? I'd wager most people wouldn't, preferring to stay with
something known.

The concept of filled barriers has merit: I wonder why it's not used more
often(I'd wager it'd due to the expense).

--
Otto Yamamoto

Elmer

2010-02-17 02:57:27 UTC

Post by John Lansford
Sand filled crash barriers work great as long as the sand doesn't get
washed out, or in cold areas, gets wet and freezes.

In the Iowa report, that concern was noted, as well as a lack of spare
panels. They also note the panels were drilled for a straight
installation, whereas their installation was on curved slip roads.

Post by John Lansford
Probably why they haven't become very popular.

And there's a major issue. There were no data on how this barrier would
perform under severe circumstances. Would you take a risk on something
like that? I'd wager most people wouldn't, preferring to stay with
something known.
The concept of filled barriers has merit: I wonder why it's not used more
often(I'd wager it'd due to the expense).
--
Otto Yamamoto

Testing the designs in that particular location in Florida at that
particular time was a good choice that probably revealed a lot of
information. Besides being extremely busy in the daytime, the drug-
fueled party lifestyle of South Florida in the 1980's kept I-95 busy
at night as well. In addition, the worst drivers from around the world
went there to rent and/or steal cars and operate them with no
knowledge of the rules of the road. So, there was certainly plenty of
vehicles crashing into those barriers! Since there was no median
divider at all before, whatever the State tried was going to be better
than nothing at all. They also knew it would only be in place for a
few years before the major widening projects came through anyway. I
know obtaining sand for the barriers is not difficult in Florida and
I'm fairly certain freezing was never an issue either. However, the
force of politics is always more powerful than any crash.

Elmer

John Lansford

2010-02-17 09:57:44 UTC

Post by John Lansford
Sand filled crash barriers work great as long as the sand doesn't get
washed out, or in cold areas, gets wet and freezes.

In the Iowa report, that concern was noted, as well as a lack of spare
panels. They also note the panels were drilled for a straight
installation, whereas their installation was on curved slip roads.

Post by John Lansford
Probably why they haven't become very popular.

And there's a major issue. There were no data on how this barrier would
perform under severe circumstances. Would you take a risk on something
like that? I'd wager most people wouldn't, preferring to stay with
something known.
The concept of filled barriers has merit: I wonder why it's not used more
often(I'd wager it'd due to the expense).
--
Otto Yamamoto

There's a big difference between field testing a crash barrier and
testing one in a controlled environment. They're basically putting
people's lives at risk deliberately to see which barrier worked
better. IMO that's not an ethical practice at all. If they wanted to
really test the barrier, have them apply to FHWA to test it and see if
it passes their certification.

John Lansford, PE
--
John's Shop of Wood
http://wood.jlansford.net/

John Lansford

2010-02-17 09:55:56 UTC

Post by John Lansford
Sand filled crash barriers work great as long as the sand doesn't get
washed out, or in cold areas, gets wet and freezes.

Barriers are designed to deflect some; a sand barrier that's frozen
isn't going to deflect as expected, resulting in more energy being
transferred to the vehicle. That's not a good thing.

In the Iowa report, that concern was noted, as well as a lack of spare
panels. They also note the panels were drilled for a straight
installation, whereas their installation was on curved slip roads.

Post by John Lansford
Probably why they haven't become very popular.

I've seen plenty of ideas that weren't popular in the industry, but
were adopted anyway. Steel cable barriers were strongly opposed by
steel beam guardrail manufacturers, but you see them everywhere now. I
think the problem with sand filled barriers was cost, maintenance
issues and lack of secondary performance after a crash.

And there's a major issue. There were no data on how this barrier would
perform under severe circumstances. Would you take a risk on something
like that? I'd wager most people wouldn't, preferring to stay with
something known.
The concept of filled barriers has merit: I wonder why it's not used more
often(I'd wager it'd due to the expense).

FHWA won't certify a barrier unless it passes their current level of
crash testing. It may be that they tested it and the barrier did not
perform adequately.

John Lansford, PE
--
John's Shop of Wood
http://wood.jlansford.net/

Larry G

2010-02-17 11:17:38 UTC

Post by John Lansford
Sand filled crash barriers work great as long as the sand doesn't get
washed out, or in cold areas, gets wet and freezes.

Barriers are designed to deflect some; a sand barrier that's frozen
isn't going to deflect as expected, resulting in more energy being
transferred to the vehicle. That's not a good thing.

In the Iowa report, that concern was noted, as well as a lack of spare
panels. They also note the panels were drilled for a straight
installation, whereas their installation was on curved slip roads.

Post by John Lansford
Probably why they haven't become very popular.

And there's a major issue. There were no data on how this barrier would
perform under severe circumstances. Would you take a risk on something
like that? I'd wager most people wouldn't, preferring to stay with
something known.
The concept of filled barriers has merit: I wonder why it's not used more
often(I'd wager it'd due to the expense).

FHWA won't certify a barrier unless it passes their current level of
crash testing. It may be that they tested it and the barrier did not
perform adequately.

I've wondered about the sand filled barriers also. I've seen big
yellow barrels with tops placed around bridge abutments and saw one
the other day that had been hit and was shattered but the bridge
abutment had not been touched.

are sand barrels approved for some uses?

John Lansford

2010-02-18 00:48:20 UTC

Post by Larry G
I've wondered about the sand filled barriers also. I've seen big
yellow barrels with tops placed around bridge abutments and saw one
the other day that had been hit and was shattered but the bridge
abutment had not been touched.
are sand barrels approved for some uses?

That's an impact attenuator, and the sand filled barrels are accepted
by FHWA but not really recommended. Again, maintenance, settlement of
the sand, and the potential for freezing all make the sand barrels
less desirable. Attenuators are used where there's no room to put
guardrail or concrete barriers to prevent a vehicle from hitting an
obstacle. The ones we tend to use are named the "GREAT system", where
GREAT is an acronym for some description or other. It's a fairly
narrow design, about 3' wide, with crushable foam sections in a frame
designed to compress. The foam sections get denser as you approach
the obstacle, so the vehicle is decelerated safely before it reaches
the rigid object.

John Lansford, PE
--
John's Shop of Wood
http://wood.jlansford.net/

Larry G

2010-02-18 15:19:17 UTC

this is what you mean - right?

Loading Image...

what does freezing do to them?

why couldn't you use some version of these as replaceable guardrails?

seems like they would absorb the crash.. but then have enough give to
keep the car from being directed back... no?

Elmer

2010-02-18 17:19:25 UTC

Post by John Lansford
That's an impact attenuator, and the sand filled barrels are accepted
by FHWA but not really recommended. Again, maintenance, settlement of
the sand, and the potential for freezing all make the sand barrels
less desirable.

this is what you mean - right?
http://traffixdevices.com/tdiprodpics/bigsandy/array2.jpg
what does freezing do to them?

If the barrels are covered, dry sand doesn't freeze. Sure, they'd need
routine, but very simple maintenance. Unfortunately, routine (and
preventive) maintenance has gone completely out of fashion, in favor
of letting infrastructure decay to the point where it requires major
rebuilding. It costs much more in the long run, but periodically
issuing lucrative private contracts has more political value than
keeping hard-working craftsman knowledgeable with the structures,
maintaining things on an ongoing basis.

Elmer

John Lansford

2010-02-18 22:50:21 UTC

this is what you mean - right?
http://traffixdevices.com/tdiprodpics/bigsandy/array2.jpg
what does freezing do to them?

If the barrels are covered, dry sand doesn't freeze.

Until someone bumps the barrel, or heat/cold causes the top to get
loose, or a hole gets in the top. Believe me, there's a very good
reason why sand attenuators are not recommended where temperatures
routinely get below freezing; there's always a chance that the sand
can get wet.

Post by Elmer
Sure, they'd need
routine, but very simple maintenance. Unfortunately, routine (and
preventive) maintenance has gone completely out of fashion, in favor
of letting infrastructure decay to the point where it requires major
rebuilding.

Uhhh, no. Maintenance money comes out of a different revenue source
than construction does, and more and more roads with more and more
traffic means more and more maintenance.

Post by Elmer
It costs much more in the long run, but periodically
issuing lucrative private contracts has more political value than
keeping hard-working craftsman knowledgeable with the structures,
maintaining things on an ongoing basis.

Do you work in the highway design/construction industry? Because your
claims don't make sense compared to what I've seen over the last 25
years.

John Lansford, PE
--
John's Shop of Wood
http://wood.jlansford.net/

Elmer

2010-02-19 03:34:13 UTC

this is what you mean - right?
http://traffixdevices.com/tdiprodpics/bigsandy/array2.jpg
what does freezing do to them?

If the barrels are covered, dry sand doesn't freeze.

Uhhh, no. Maintenance money comes out of a different revenue source
than construction does, and more and more roads with more and more
traffic means more and more maintenance.

Do you work in the highway design/construction industry? Because your
claims don't make sense compared to what I've seen over the last 25
years.
John Lansford, PE
--
John's Shop of Woodhttp://wood.jlansford.net/

Curiously, just tonight I noticed a whole array of those barrels on
US-1 at the exit for Salem Street in Saugus Massachusetts. (Just north
of the Copeland Circle interchange, with it's famous ghost ramps for
where I-95 was never completed.)

Being this is Masachusetts, I ain't sayin' they work perfectly, but we
certainly do get freezing weather. The barrels are at a particularly
dangerous exit with very tight ramps. Even discounting the human toll
(which we shouldn't), there's got to be a cost-benefit ratio that
justifies using the barrels if the alternative is vehicles constantly
crashing into a bridge abutment or other structure and causing much
more expensive damage. (Either that, or more likely, somebody's
brother-in-law works for the company that makes the barrels.)

Regarding the maintenance issue, John, it's much worse here in
Massachusetts than any other place I've ever lived. Wildly expensive
projects are built, with no consideration for keeping them maintained.
Subway stations and even bus stops are constructed to "make an
architectural statement" and incorporate custom designs that cost more
initially, and a lot more in the long-run. But what good are custom
light fixtures if you can't keep them lit? I think most people who use
public transportation would be quite happy with the same kind of light
fixtures used at their supermarket, but be much more impressed if the
station was clean and their bus (any bus) simply arrived on time.

Meanwhile, I see simple, inexpensive maintenance being completely
ignored. Knowing you are familiar with the properties of freezing
water, I'm sure you can appreciate how destructive freeze-thaw cycles
can be, especially to concrete and when combined with road salt.
Pointing up small cracks is a never-ending job, but it pays off by
lengthening the life of the structure. There are some very beautiful
bridges here that I almost think are being deliberately allowed to
decay, if not actually encouraged. I guess that's what really bother's
me the most.

The poor Longfellow bridge is my favorite example. This beautiful
bridge is truly an icon of Boston. It carries cars, the Red Line
subway and pedestrians across the Charles river. Between the weeds
growing in the cracks in the summer, and the freeze-thaw cycles in the
winter it crumbles and sags more and more every year. Adding further
insult to it's injuries, State employees charged with it's maintenance
stole and sold for scrap irreplaceable ironwork from the bridge two
years ago. It's sad, it's really sad:

http://www.flickr.com/photos/elmercat/sets/72157607251942412/

Oh, and then there's this little tunnel in Boston, maybe you've heard
about...

Elmer

Larry G

2010-02-19 10:34:47 UTC

this is what you mean - right?
http://traffixdevices.com/tdiprodpics/bigsandy/array2.jpg
what does freezing do to them?

If the barrels are covered, dry sand doesn't freeze.

Uhhh, no. Maintenance money comes out of a different revenue source
than construction does, and more and more roads with more and more
traffic means more and more maintenance.

Do you work in the highway design/construction industry? Because your
claims don't make sense compared to what I've seen over the last 25
years.
John Lansford, PE
--
John's Shop of Woodhttp://wood.jlansford.net/

Curiously, just tonight I noticed a whole array of those barrels on
US-1 at the exit for Salem Street in Saugus Massachusetts. (Just north
of the Copeland Circle interchange, with it's famous ghost ramps for
where I-95 was never completed.)
Being this is Masachusetts, I ain't sayin' they work perfectly, but we
certainly do get freezing weather. The barrels are at a particularly
dangerous exit with very tight ramps. Even discounting the human toll
(which we shouldn't), there's got to be a cost-benefit ratio that
justifies using the barrels if the alternative is vehicles constantly
crashing into a bridge abutment or other structure and causing much
more expensive damage. (Either that, or more likely, somebody's
brother-in-law works for the company that makes the barrels.)
Regarding the maintenance issue, John, it's much worse here in
Massachusetts than any other place I've ever lived. Wildly expensive
projects are built, with no consideration for keeping them maintained.
Subway stations and even bus stops are constructed to "make an
architectural statement" and incorporate custom designs that cost more
initially, and a lot more in the long-run. But what good are custom
light fixtures if you can't keep them lit? I think most people who use
public transportation would be quite happy with the same kind of light
fixtures used at their supermarket, but be much more impressed if the
station was clean and their bus (any bus) simply arrived on time.
Meanwhile, I see simple, inexpensive maintenance being completely
ignored. Knowing you are familiar with the properties of freezing
water, I'm sure you can appreciate how destructive freeze-thaw cycles
can be, especially to concrete and when combined with road salt.
Pointing up small cracks is a never-ending job, but it pays off by
lengthening the life of the structure. There are some very beautiful
bridges here that I almost think are being deliberately allowed to
decay, if not actually encouraged. I guess that's what really bother's
me the most.
The poor Longfellow bridge is my favorite example. This beautiful
bridge is truly an icon of Boston. It carries cars, the Red Line
subway and pedestrians across the Charles river. Between the weeds
growing in the cracks in the summer, and the freeze-thaw cycles in the
winter it crumbles and sags more and more every year. Adding further
insult to it's injuries, State employees charged with it's maintenance
stole and sold for scrap irreplaceable ironwork from the bridge two
http://www.flickr.com/photos/elmercat/sets/72157607251942412/
Oh, and then there's this little tunnel in Boston, maybe you've heard
about...

building new roads is sexy... maintenance not so much...

Elmer

2010-02-19 16:27:42 UTC

Post by Larry G
building new roads is sexy... maintenance not so much...

I agree, Larry, that sums it up very well. I think it's the biggest
problem standing in the way of keeping our infrastructure sound and
efficient. There's never enough money to replace every aging or
substandard bridge, but maintaining and/or improving what we already
have would go a lot farther. Unfortunately, those with the power to
make such decisions are suckers for the smell of sizzling bacon and
have no foresight into the consequential heart failure it leads to.

Elmer

John Lansford

2010-02-19 10:47:46 UTC

this is what you mean - right?
http://traffixdevices.com/tdiprodpics/bigsandy/array2.jpg
what does freezing do to them?

If the barrels are covered, dry sand doesn't freeze.

Uhhh, no. Maintenance money comes out of a different revenue source
than construction does, and more and more roads with more and more
traffic means more and more maintenance.

Do you work in the highway design/construction industry? Because your
claims don't make sense compared to what I've seen over the last 25
years.

Are you sure they've got sand in them? Water is also used in
attenuators, and there are treatments that will keep water from
freezing.

Post by Elmer
Being this is Masachusetts, I ain't sayin' they work perfectly, but we
certainly do get freezing weather. The barrels are at a particularly
dangerous exit with very tight ramps. Even discounting the human toll
(which we shouldn't), there's got to be a cost-benefit ratio that
justifies using the barrels if the alternative is vehicles constantly
crashing into a bridge abutment or other structure and causing much
more expensive damage. (Either that, or more likely, somebody's
brother-in-law works for the company that makes the barrels.)

I'm not saying they aren't worth it. I'm saying there are better
alternatives that require less maintenance and don't run the risk of
freezing weather.

John Lansford, PE
--
John's Shop of Wood
http://wood.jlansford.net/

Larry G

2010-02-19 11:11:55 UTC

this is what you mean - right?
http://traffixdevices.com/tdiprodpics/bigsandy/array2.jpg
what does freezing do to them?

If the barrels are covered, dry sand doesn't freeze.

Uhhh, no. Maintenance money comes out of a different revenue source
than construction does, and more and more roads with more and more
traffic means more and more maintenance.

Do you work in the highway design/construction industry? Because your
claims don't make sense compared to what I've seen over the last 25
years.

Are you sure they've got sand in them? Water is also used in
attenuators, and there are treatments that will keep water from
freezing.

I'm not saying they aren't worth it. I'm saying there are better
alternatives that require less maintenance and don't run the risk of
freezing weather.

If sand is not the right material then why not some other material?
Isn't the point here to provide something that has advantages over
metal and concrete as a barrier?

NASCAR went through years and years insisting that concrete and metal
was just fine as a barrier until they lost Dale Earnheardt and finally
got religion.

I think the current jersey walls and metal guardrails are the right
approach in some areas but perhaps not as good as sand-like (if you
don't like pure sand) barriers in other areas.

It sure seems that one big advantages of sand-like barriers is that
you don't need to be as concerned with the height of the barrier like
you are with metal and concrete.

and really as far as freezing is concerned.. would a frozen sand
barrier be any worse than concrete anyhow?

Andrew Tompkins

2010-02-19 18:31:33 UTC

this is what you mean - right?
http://traffixdevices.com/tdiprodpics/bigsandy/array2.jpg
what does freezing do to them?

If the barrels are covered, dry sand doesn't freeze.

Uhhh, no. Maintenance money comes out of a different revenue source
than construction does, and more and more roads with more and more
traffic means more and more maintenance.

Do you work in the highway design/construction industry? Because your
claims don't make sense compared to what I've seen over the last 25
years.

Are you sure they've got sand in them? Water is also used in
attenuators, and there are treatments that will keep water from
freezing.

I'm not saying they aren't worth it. I'm saying there are better
alternatives that require less maintenance and don't run the risk of
freezing weather.

SAFER barrier didn't come out as a result of the DE crash in 2001 (that
led to the mandatory use of the HANS device). The fact that SAFER
barrier was first in place half way through the next season is merely
coincidence. They had been working on it for several years prior to
that and had prototype energy absorbing barriers in place in 1998. They
still don't use it all the way around the track (only on the curves).

--Andy

Larry G

2010-02-20 00:21:58 UTC

this is what you mean - right?
http://traffixdevices.com/tdiprodpics/bigsandy/array2.jpg
what does freezing do to them?

If the barrels are covered, dry sand doesn't freeze.

Uhhh, no. Maintenance money comes out of a different revenue source
than construction does, and more and more roads with more and more
traffic means more and more maintenance.

Do you work in the highway design/construction industry? Because your
claims don't make sense compared to what I've seen over the last 25
years.

Are you sure they've got sand in them? Water is also used in
attenuators, and there are treatments that will keep water from
freezing.

I'm not saying they aren't worth it. I'm saying there are better
alternatives that require less maintenance and don't run the risk of
freezing weather.

you're correct.. I stand corrected. and yes.. also to the selective
placement of the SAFER barriers... but IIRC.. there were some major
bad accidents that motivated them to go to SAFER barriers.

John Lansford

2010-02-20 04:32:22 UTC

Post by Larry G
you're correct.. I stand corrected. and yes.. also to the selective
placement of the SAFER barriers... but IIRC.. there were some major
bad accidents that motivated them to go to SAFER barriers.

Cars heavier than what's on the road, travelling at speeds nowhere
close to highway speeds, and on relatively few road-miles needing
barriers. It's unrealistic to think similar barriers could perform as
well on the public roads, and certainly not without a prohibitive
cost.

John Lansford, PE
--
John's Shop of Wood
http://wood.jlansford.net/

Andrew Tompkins

2010-02-20 05:51:11 UTC

this is what you mean - right?
http://traffixdevices.com/tdiprodpics/bigsandy/array2.jpg
what does freezing do to them?

If the barrels are covered, dry sand doesn't freeze.

Uhhh, no. Maintenance money comes out of a different revenue source
than construction does, and more and more roads with more and more
traffic means more and more maintenance.

Do you work in the highway design/construction industry? Because your
claims don't make sense compared to what I've seen over the last 25
years.

Are you sure they've got sand in them? Water is also used in
attenuators, and there are treatments that will keep water from
freezing.

I'm not saying they aren't worth it. I'm saying there are better
alternatives that require less maintenance and don't run the risk of
freezing weather.

you're correct.. I stand corrected. and yes.. also to the selective
placement of the SAFER barriers... but IIRC.. there were some major
bad accidents that motivated them to go to SAFER barriers.

No doubt. On the SAFER barrier web page on the NASCAR website, they
have a video clip where the car, on a qualifying lap, crashes into the
SAFER barrier at about a 50 degree angle at 180 MPH and rolls about 8
times. The driver climbs out of the leftover safety cage and walks away
from a scattered pile of car parts. A testament to the safety items
built into both the track and the cars.

But SAFER barrier is probably still way too expensive to use on roads
and hwys.

--Andy

Larry G

2010-02-20 12:24:57 UTC

this is what you mean - right?
http://traffixdevices.com/tdiprodpics/bigsandy/array2.jpg
what does freezing do to them?

If the barrels are covered, dry sand doesn't freeze.

Uhhh, no. Maintenance money comes out of a different revenue source
than construction does, and more and more roads with more and more
traffic means more and more maintenance.

Do you work in the highway design/construction industry? Because your
claims don't make sense compared to what I've seen over the last 25
years.

Are you sure they've got sand in them? Water is also used in
attenuators, and there are treatments that will keep water from
freezing.

I'm not saying they aren't worth it. I'm saying there are better
alternatives that require less maintenance and don't run the risk of
freezing weather.

you're correct.. I stand corrected. and yes.. also to the selective
placement of the SAFER barriers... but IIRC.. there were some major
bad accidents that motivated them to go to SAFER barriers.

No doubt. On the SAFER barrier web page on the NASCAR website, they
have a video clip where the car, on a qualifying lap, crashes into the
SAFER barrier at about a 50 degree angle at 180 MPH and rolls about 8
times. The driver climbs out of the leftover safety cage and walks away
from a scattered pile of car parts. A testament to the safety items
built into both the track and the cars.
But SAFER barrier is probably still way too expensive to use on roads
and hwys.

The NASCAR SAFER Barrier as currently designed - yes. But what about
the design - modified for public highway use? Couldn't a barrier than
incorporates the design features but altered for lower speed crashes
be worth exploring? I note that many features found in common usage
often are first looked at in racing and other extreme environments and
uses.

What is it about the SAFER barrier that makes it different or unique
with respect to typical public highway barriers?

John Lansford

2010-02-20 14:04:20 UTC

Post by Larry G
The NASCAR SAFER Barrier as currently designed - yes. But what about
the design - modified for public highway use? Couldn't a barrier than
incorporates the design features but altered for lower speed crashes
be worth exploring? I note that many features found in common usage
often are first looked at in racing and other extreme environments and
uses.
What is it about the SAFER barrier that makes it different or unique
with respect to typical public highway barriers?

I'm trying to figure out why you are trying to 'reinvent the wheel'
here, Larry. Steel guardrail is relatively cheap, easy to install,
durable, does what it is designed to do, easy to maintain and has a
robust secondary effect even after it's been struck once.

Show me something that is as comparable to all that and maybe you'll
have something, but so far (sand piles, sand barrels, now expensive
custom designed NASCAR barriers) you've failed every time.

John Lansford, PE
--
John's Shop of Wood
http://wood.jlansford.net/

Elmer

2010-02-20 20:12:21 UTC

On Feb 20, 9:04 am, John Lansford <***@bellsouth.net> wrote:
Steel guardrail is relatively cheap, easy to install,

Post by John Lansford
durable, does what it is designed to do, easy to maintain and has a
robust secondary effect even after it's been struck once.
Show me something that is as comparable to all that and maybe you'll
have something, but so far (sand piles, sand barrels, now expensive
custom designed NASCAR barriers) you've failed every time.

The International Barrier Corporation's Mark VII barrier (that was in
my mind when I began the thread branch) had all the great properties
of steel that you cite above, plus the additional energy absorbing
feature of it's sand ballast filling. As has been pointed out, the
test results from Florida are sparsely mentioned in the Virginia
report. It would be interesting to see all the data.

Searching the archives of the Miami Herald, I found two relevant
references (below) that pinpoint the date. They had been planned by
the end of 1982, and were being installed in 1983. I didn't pay to
read the full articles, but if someone does, I'm fairly certain the
first article will confirm that two crash barrier designs were being
evaluated. In addition to the concrete barrier ("similar to Dade
County"), the innovation in the pun riddled article title refers to
the sand-filled steel design that would be tried in just one area of
Broward's I-95.

I also included a third reference that brings reality into why all of
this is worthwhile! I don't know what kind of barrier was the hero in
that particular accident. But why shouldn't we always keep trying to
make things better?

Elmer

From Archives of Miami Herald (searched for "I-95 crash barrier")

Miami Herald - November 16, 1982 - 2BR BRWD N
INNOVATIVE DOT BREAKING BARRIERS WITH I-95 PROJECT
Interstate highways were designed to provide high-speed travel in
relative safety. Anyone who drives on Interstate 95 in Broward County
knows the reality is quite different. In response to a series of
grisly fatal crashes caused by cars crossing the narrow median strip,
the state Department of Transportation will install a concrete barrier
to block vehicles from veering into oncoming traffic on I-95. The
barrier, similar to the one along Dade's portion of I- 95, is..

Miami Herald - July 7, 1983 - 2BR BRWD N EDITORIAL
I-95 BARRIER WORK IS WELL WORTH THE INCONVENIENCE
The traffic jams that have become daily fare on Interstate 95 south of
Broward Boulevard inconvenience hundreds of thousands of drivers. But
a higher purpose is being served. As construction crews install a
barrier along the median strip in the 10-mile stretch south to the
Dade County line, they are helping to save lives. The $1.4-million
barrier was ordered after a spate of grisly cross-median accidents.
Thirteen persons died along that stretch of I-95 in cross-median
crashes in...

Miami Herald - June 27, 1986 - 1BR BRWD N
SAFETY BARRIER SPARES STUDENTS IN I-95 BUS FLIP
A school bus that crashed Thursday on Interstate 95 had a good driver,
good brakes and the good fortune to crash into a safety barrier,
allowing most of the 45 college students on board to escape with minor
injuries from what could have been a disaster. "It's a miracle that
more persons were not more seriously injured or even killed," said
Florida Highway Patrol Capt. Rich Rossman. A motorist apparently cut
in front of the bus at 8:43 a.m. in a...

John Lansford

2010-02-20 20:49:34 UTC

Post by Elmer
Steel guardrail is relatively cheap, easy to install,

The International Barrier Corporation's Mark VII barrier (that was in
my mind when I began the thread branch) had all the great properties
of steel that you cite above,

Except your own earlier articles said it was more expensive than
steel, and from the descriptions it takes up more room than a steel
barrier. Both of those are big reasons why steel guardrail is used
over a bunch of sand filled barrels. That FHWA has not certified such
a design for use on anything but as a crash attenuator at localized
sites tells me it is not competitive with the current designs.

John Lansford, PE
--
John's Shop of Wood
http://wood.jlansford.net/

Elmer

2010-02-21 05:18:13 UTC

Post by Elmer
Steel guardrail is relatively cheap, easy to install,

The International Barrier Corporation's Mark VII barrier (that was in
my mind when I began the thread branch) had all the great properties
of steel that you cite above,

Except your own earlier articles said it was more expensive than
steel, and from the descriptions it takes up more room than a steel
barrier. Both of those are big reasons why steel guardrail is used
over a bunch of sand filled barrels. That FHWA has not certified such
a design for use on anything but as a crash attenuator at localized
sites tells me it is not competitive with the current designs.
John Lansford, PE
--
John's Shop of Woodhttp://wood.jlansford.net/

Well now, wait a minute. First of all, the median divider crash
barrier product I'm talking about, was being evaluated nearly 20 years
ago. (It has nothing to do with the NASCAR barrier Larry brought up.)
Second, it was made of steel. The competing product was made of
concrete and didn't have all those great characteristics of steel that
you listed. Yes, it was more expensive than standard steel guard rail,
but so was concrete. My opinion all along has been that the powerful
cement lobby in Florida influenced the State's decision to choose
concrete, even though it wasn't the safest.

Sand filled barrels are used for a completely different purpose, not
as a dividing barrier, but as an impact absorbing buffer in front of
an abutment or other structure, in locations prone to vehicles
crashing into it. I noticed another array of them just tonight,
located on MA-99 at the tunnel that goes underneath Sullivan Square in
Boston. Unlike the barrels I saw on US-1 the other night, these
barrels have been crashed into at least once, but probably many times.
They definitely contained sand; there was a lot of it scattered around
the smashed plastic barrels, which are not much more than large
glorified garbage cans. Freezing is clearly not a major problem, if at
all. (perhaps a certain grade of sand minimizes it?) Even in this
sorry looking condition, they still appear to offer some protection.
I'm sure they'll get hit even more times before anyone gets around to
replacing, repairing or even refilling the barrels. Yet, it's still
better than hitting the abutment directly.

Elmer

John Lansford

2010-02-21 13:56:10 UTC

Post by Elmer
Well now, wait a minute. First of all, the median divider crash
barrier product I'm talking about, was being evaluated nearly 20 years
ago. (It has nothing to do with the NASCAR barrier Larry brought up.)
Second, it was made of steel. The competing product was made of
concrete and didn't have all those great characteristics of steel that
you listed. Yes, it was more expensive than standard steel guard rail,
but so was concrete. My opinion all along has been that the powerful
cement lobby in Florida influenced the State's decision to choose
concrete, even though it wasn't the safest.

Concrete also has zero maintenance needs, as opposed to something that
requires reconstruction after an impact. It's why the standard narrow
median barrier nationwide is concrete instead of something else, like
steel boxes full of sand, or water, or foam, or anything non-concrete.
Also, concrete median barriers are 2' wide; this steel/sand barrier
looked to be at least twice that in width.

Post by Elmer
Sand filled barrels are used for a completely different purpose, not
as a dividing barrier, but as an impact absorbing buffer in front of
an abutment or other structure, in locations prone to vehicles
crashing into it.

Yes, they are called impact attenuators. When I took a course on
impact attenuators, the FHWA instructor pointed out that sand barrels
don't work on the corners, where there aren't enough sand barrels to
adequately prevent a vehicle from reaching the obstacle. There are
some designs that meet the Type 350 crash tests but their use is
fairly limited.

Post by Elmer
I noticed another array of them just tonight,
located on MA-99 at the tunnel that goes underneath Sullivan Square in
Boston. Unlike the barrels I saw on US-1 the other night, these
barrels have been crashed into at least once, but probably many times.
They definitely contained sand; there was a lot of it scattered around
the smashed plastic barrels, which are not much more than large
glorified garbage cans. Freezing is clearly not a major problem, if at
all. (perhaps a certain grade of sand minimizes it?) Even in this
sorry looking condition, they still appear to offer some protection.

Plus the sand now is going to get spread all over the place, making
the lanes hazardous, and the maintenance is basically "pick up all
this mess, throw it away and put brand new pieces back". In the
modular attenuators I've seen, the only parts that get replaced are
the foam bricks that are designed to be crushed; everything else is
reusable.

Post by Elmer
I'm sure they'll get hit even more times before anyone gets around to
replacing, repairing or even refilling the barrels. Yet, it's still
better than hitting the abutment directly.

So would piling a lot of tires in front of the abutment but that
doesn't mean it's a good alternative to other options, though.

Here's some links; notice most of them recommend sand barrels for
TEMPORARY locations, and if the extra width required for them isn't
available, a different type has to be required.

http://epg.modot.org/index.php?title=Category:612_Impact_Attenuators

http://safety.fhwa.dot.gov/roadway_dept/policy_guide/road_hardware/nchrp_350/catg3.cfm
" * Sand Barrel attenuators usually require complete replacement.
Should be used where you have the available width, and the frequency
of impact will be low
* More sophisticated attenuators are expensive, but easier to
repair. They should be used when working widths are narrow and
frequency of hits is likely to be high"

http://safety.fhwa.dot.gov/roadway_dept/policy_guide/road_hardware/listing.cfm

Here's a link to the entire list of approved crash barriers, both
longitudinal and attenuators, from FHWA. Sand barriers have very
limited application:

http://safety.fhwa.dot.gov/roadway_dept/policy_guide/road_hardware/

John Lansford, PE
--
John's Shop of Wood
http://wood.jlansford.net/

Andrew Tompkins

2010-02-20 17:48:13 UTC

this is what you mean - right?
http://traffixdevices.com/tdiprodpics/bigsandy/array2.jpg
what does freezing do to them?

If the barrels are covered, dry sand doesn't freeze.

Uhhh, no. Maintenance money comes out of a different revenue source
than construction does, and more and more roads with more and more
traffic means more and more maintenance.

Do you work in the highway design/construction industry? Because your
claims don't make sense compared to what I've seen over the last 25
years.

Are you sure they've got sand in them? Water is also used in
attenuators, and there are treatments that will keep water from
freezing.

I'm not saying they aren't worth it. I'm saying there are better
alternatives that require less maintenance and don't run the risk of
freezing weather.

you're correct.. I stand corrected. and yes.. also to the selective
placement of the SAFER barriers... but IIRC.. there were some major
bad accidents that motivated them to go to SAFER barriers.

No doubt. On the SAFER barrier web page on the NASCAR website, they
have a video clip where the car, on a qualifying lap, crashes into the
SAFER barrier at about a 50 degree angle at 180 MPH and rolls about 8
times. The driver climbs out of the leftover safety cage and walks away
from a scattered pile of car parts. A testament to the safety items
built into both the track and the cars.
But SAFER barrier is probably still way too expensive to use on roads
and hwys.

The NASCAR SAFER Barrier as currently designed - yes. But what about
the design - modified for public highway use? Couldn't a barrier than
incorporates the design features but altered for lower speed crashes
be worth exploring? I note that many features found in common usage
often are first looked at in racing and other extreme environments and
uses.
What is it about the SAFER barrier that makes it different or unique
with respect to typical public highway barriers?

In its current design, SAFER barrier doesn't look like is would scale
down very well. It's essentially steel configured to include airspace
for crumpling mounted on an attenuator of some type, which, when scaled
down with redesign, is essentially what steel beam guardrail is when
mounted on posts (not jersey barriers).

--Andy

Larry G

2010-02-21 20:18:39 UTC

this is what you mean - right?
http://traffixdevices.com/tdiprodpics/bigsandy/array2.jpg
what does freezing do to them?

If the barrels are covered, dry sand doesn't freeze.

Uhhh, no. Maintenance money comes out of a different revenue source
than construction does, and more and more roads with more and more
traffic means more and more maintenance.

Do you work in the highway design/construction industry? Because your
claims don't make sense compared to what I've seen over the last 25
years.

Are you sure they've got sand in them? Water is also used in
attenuators, and there are treatments that will keep water from
freezing.

I'm not saying they aren't worth it. I'm saying there are better
alternatives that require less maintenance and don't run the risk of
freezing weather.

you're correct.. I stand corrected. and yes.. also to the selective
placement of the SAFER barriers... but IIRC.. there were some major
bad accidents that motivated them to go to SAFER barriers.

No doubt. On the SAFER barrier web page on the NASCAR website, they
have a video clip where the car, on a qualifying lap, crashes into the
SAFER barrier at about a 50 degree angle at 180 MPH and rolls about 8
times. The driver climbs out of the leftover safety cage and walks away
from a scattered pile of car parts. A testament to the safety items
built into both the track and the cars.
But SAFER barrier is probably still way too expensive to use on roads
and hwys.

The NASCAR SAFER Barrier as currently designed - yes. But what about
the design - modified for public highway use? Couldn't a barrier than
incorporates the design features but altered for lower speed crashes
be worth exploring? I note that many features found in common usage
often are first looked at in racing and other extreme environments and
uses.
What is it about the SAFER barrier that makes it different or unique
with respect to typical public highway barriers?

alright.. I saw the water-filled barriers... interesting... how about
foam-filled?

I guess at the end of the day - as John as been saying... it's the
combination of factors, cost, maintenance and effectiveness... I
guess those DOT guys know their business... eh?

Andrew Tompkins

2010-02-22 02:17:54 UTC

this is what you mean - right?
http://traffixdevices.com/tdiprodpics/bigsandy/array2.jpg
what does freezing do to them?

If the barrels are covered, dry sand doesn't freeze.

Uhhh, no. Maintenance money comes out of a different revenue source
than construction does, and more and more roads with more and more
traffic means more and more maintenance.

Do you work in the highway design/construction industry? Because your
claims don't make sense compared to what I've seen over the last 25
years.

Are you sure they've got sand in them? Water is also used in
attenuators, and there are treatments that will keep water from
freezing.

I'm not saying they aren't worth it. I'm saying there are better
alternatives that require less maintenance and don't run the risk of
freezing weather.

you're correct.. I stand corrected. and yes.. also to the selective
placement of the SAFER barriers... but IIRC.. there were some major
bad accidents that motivated them to go to SAFER barriers.

No doubt. On the SAFER barrier web page on the NASCAR website, they
have a video clip where the car, on a qualifying lap, crashes into the
SAFER barrier at about a 50 degree angle at 180 MPH and rolls about 8
times. The driver climbs out of the leftover safety cage and walks away
from a scattered pile of car parts. A testament to the safety items
built into both the track and the cars.
But SAFER barrier is probably still way too expensive to use on roads
and hwys.

The NASCAR SAFER Barrier as currently designed - yes. But what about
the design - modified for public highway use? Couldn't a barrier than
incorporates the design features but altered for lower speed crashes
be worth exploring? I note that many features found in common usage
often are first looked at in racing and other extreme environments and
uses.
What is it about the SAFER barrier that makes it different or unique
with respect to typical public highway barriers?

alright.. I saw the water-filled barriers... interesting... how about
foam-filled?

Why? The foam is probably no more effective than water and the water is
easier to clean up and replace after use.

Post by Larry G
I guess at the end of the day - as John as been saying... it's the
combination of factors, cost, maintenance and effectiveness... I
guess those DOT guys know their business... eh?

Better than me. :-)

--Andy

John Lansford

2010-02-19 18:34:41 UTC

Post by Larry G
If sand is not the right material then why not some other material?
Isn't the point here to provide something that has advantages over
metal and concrete as a barrier?

Don't you think these "other materials" have been researched? Or do
you think that you're the only person who's thought about this so far?

Look, you've got several different criteria for a crash barrier to be
viable. It has to first off, work. That means passing FHWA's crash
tests.

Second, it has to be easy to maintain; I've seen designs that passed
the crash tests but were so complicated the maintenance had to be done
by specially trained technicians.

Third, it has to be fairly inexpensive to build. It won't do any good
if you come up with a barrier that works as well as guardrail but it
is 5x more expensive.

Post by Larry G
NASCAR went through years and years insisting that concrete and metal
was just fine as a barrier until they lost Dale Earnheardt and finally
got religion.

Still use concrete and metal too, now don't they? The netting above
the concrete walls is there to catch vehicular debris from making it
into the crowd, anyway.

Post by Larry G
I think the current jersey walls and metal guardrails are the right
approach in some areas but perhaps not as good as sand-like (if you
don't like pure sand) barriers in other areas.

So name one of these places, Larry, because in 26 years of design work
I can't think of any situation where a pile of sand would have worked
better than what I proposed.

Post by Larry G
It sure seems that one big advantages of sand-like barriers is that
you don't need to be as concerned with the height of the barrier like
you are with metal and concrete.

Really? So how deep do you think this pile of sand needs to be? Would
six inches of sand be enough? How about a foot? Maybe two foot would
be enough? Oh, wait; guardrail is only 28" high, so we're already at
that height, aren't we? Except, the guardrail takes up 2' of lateral
width, while 2' of sand needs about 6'-8' of width to get a stable
pile.

The ONLY place I have ever seen a pile of sand used as a crash barrier
was at the end of a short truck escape ramp, as a 'final solution' if
the truck didn't stop in the escape ramp itself. That's it.

Post by Larry G
and really as far as freezing is concerned.. would a frozen sand
barrier be any worse than concrete anyhow?

Yes it would, because a sloping frozen pile of sand looks a lot like a
launching ramp. A concrete wall stays vertical no matter the weather.

Or have you already forgotten about sand's tendency to become a gently
sloping pile of material?

John Lansford, PE
--
John's Shop of Wood
http://wood.jlansford.net/

John Lansford

2010-02-18 22:47:03 UTC

this is what you mean - right?
http://traffixdevices.com/tdiprodpics/bigsandy/array2.jpg
what does freezing do to them?

Makes them as hard as concrete if the sand gets wet. Still want to
run into them?

Post by Larry G
why couldn't you use some version of these as replaceable guardrails?

Becanse once something hits one of them, they become useless, they
make a damn big mess when someone does hit them, the plastic degrades
over time due to heat/cold, UV light and minor impacts, and they're
expensive.

Post by Larry G
seems like they would absorb the crash.. but then have enough give to
keep the car from being directed back... no?

They absorb impact because there's a lot of them. Guardrail takes up
2' and deflects about 5' when hit. Those things take up about 10-20'
depending on the speed and weight of vehicle you want to absorb impact
from. IIRC the last time I priced one of those attenuators the cost
was about $10,000 for just one site protected. Guardrail costs about
$15/foot. Do the math.

John Lansford, PE
--
John's Shop of Wood
http://wood.jlansford.net/

Larry G

2010-02-18 23:03:44 UTC

this is what you mean - right?
http://traffixdevices.com/tdiprodpics/bigsandy/array2.jpg
what does freezing do to them?

Makes them as hard as concrete if the sand gets wet. Still want to
run into them?

Post by Larry G
why couldn't you use some version of these as replaceable guardrails?

Post by Larry G
seems like they would absorb the crash.. but then have enough give to
keep the car from being directed back... no?

okay.. I buy it.. another question for you

if the shoulder is sloped down and then it ends up with a sand
berm...won't that capture and hold a wayward vehicle and not send it
back out into traffic?

I can see guardrails used in tight r/w but what about all those miles
of divided highways with substantial medians?

now be nice.. I'm asking a polite question here...

:-)

John Lansford

2010-02-18 23:47:49 UTC

Post by Larry G
okay.. I buy it.. another question for you
if the shoulder is sloped down and then it ends up with a sand
berm...won't that capture and hold a wayward vehicle and not send it
back out into traffic?

Sand has a very low angle of repose. That's the angle the material
will tend to try and get to if you leave it alone. Sand has an angle
of repose somewhere between 3:1 and 2:1, depending on the angularity
of the grains and how wet it is.

Since you're now talking about a "sand berm", I'm assuming you mean a
pile of sand at the edge of the shoulder running parallel to the
lanes. When the sand gets wet, it will slump down to that angle of
repose, then it will freeze, it will also trap debris along the
shoulder, and eventually trap water, which will also freeze. You'll
need a pretty big pile of sand to stop a car at 70mph, probably at
least 4-5' high. With an angle of repose at 3:1, that's 30' of
property to pile the sand up 5' (15' on each side).

Post by Larry G
I can see guardrails used in tight r/w but what about all those miles
of divided highways with substantial medians?

Where is the water going to go? Those medians are depressed at least
2' to keep the water out of the pavement structure. A pile of sand
30' wide is going to raise the water level, trap it against the
shoulder, require CONSTANT maintenance to keep it sloped properly (and
cleaned), etc, etc.

There's a really good reason why truck escape ramps don't use sand in
the arrester bed unless there's no other way to build them; it freezes
and requires a lot of work to make it function correctly, and it tends
to tear the understructure off the truck when it does work properly.

Perhaps if you made the median a lot wider and just put a lot of loose
sand in it, and didn't have a lot of rain to worry about (or
freezing), it might work, but even in Florida there are land
restrictions as well as freezing concerns for at least half the state.

John Lansford, PE
--
John's Shop of Wood
http://wood.jlansford.net/

Larry G

2010-02-19 00:14:58 UTC

Sand has a very low angle of repose. That's the angle the material
will tend to try and get to if you leave it alone. Sand has an angle
of repose somewhere between 3:1 and 2:1, depending on the angularity
of the grains and how wet it is.
Since you're now talking about a "sand berm", I'm assuming you mean a
pile of sand at the edge of the shoulder running parallel to the
lanes. When the sand gets wet, it will slump down to that angle of
repose, then it will freeze, it will also trap debris along the
shoulder, and eventually trap water, which will also freeze. You'll
need a pretty big pile of sand to stop a car at 70mph, probably at
least 4-5' high. With an angle of repose at 3:1, that's 30' of
property to pile the sand up 5' (15' on each side).

Post by Larry G
I can see guardrails used in tight r/w but what about all those miles
of divided highways with substantial medians?

Where is the water going to go? Those medians are depressed at least
2' to keep the water out of the pavement structure. A pile of sand
30' wide is going to raise the water level, trap it against the
shoulder, require CONSTANT maintenance to keep it sloped properly (and
cleaned), etc, etc.
There's a really good reason why truck escape ramps don't use sand in
the arrester bed unless there's no other way to build them; it freezes
and requires a lot of work to make it function correctly, and it tends
to tear the understructure off the truck when it does work properly.
Perhaps if you made the median a lot wider and just put a lot of loose
sand in it, and didn't have a lot of rain to worry about (or
freezing), it might work, but even in Florida there are land
restrictions as well as freezing concerns for at least half the state.

thanks... I suppose you could use pipes to convey the water but I
thought that water would not get trapped in sand to start... you can
walk on sand beaches up north in the winter and they're still not
frozen... right?

how much does a runaway truck ramp cost?

John Lansford

2010-02-19 00:31:06 UTC

Sand has a very low angle of repose. That's the angle the material
will tend to try and get to if you leave it alone. Sand has an angle
of repose somewhere between 3:1 and 2:1, depending on the angularity
of the grains and how wet it is.
Since you're now talking about a "sand berm", I'm assuming you mean a
pile of sand at the edge of the shoulder running parallel to the
lanes. When the sand gets wet, it will slump down to that angle of
repose, then it will freeze, it will also trap debris along the
shoulder, and eventually trap water, which will also freeze. You'll
need a pretty big pile of sand to stop a car at 70mph, probably at
least 4-5' high. With an angle of repose at 3:1, that's 30' of
property to pile the sand up 5' (15' on each side).

Post by Larry G
I can see guardrails used in tight r/w but what about all those miles
of divided highways with substantial medians?

Where is the water going to go? Those medians are depressed at least
2' to keep the water out of the pavement structure. A pile of sand
30' wide is going to raise the water level, trap it against the
shoulder, require CONSTANT maintenance to keep it sloped properly (and
cleaned), etc, etc.
There's a really good reason why truck escape ramps don't use sand in
the arrester bed unless there's no other way to build them; it freezes
and requires a lot of work to make it function correctly, and it tends
to tear the understructure off the truck when it does work properly.
Perhaps if you made the median a lot wider and just put a lot of loose
sand in it, and didn't have a lot of rain to worry about (or
freezing), it might work, but even in Florida there are land
restrictions as well as freezing concerns for at least half the state.

Sea water doesn't freeze at 32 degrees, and it's in motion as the surf
rolls over it. I've seen frozen sand before; the more it's contained
the easier it will freeze.

Post by Larry G
how much does a runaway truck ramp cost?

Depends on how big it is. The ones I put in on I-26 were about
$100,000 each, including the pea gravel, anchors, drain system and
approaches.

John Lansford, PE
--
John's Shop of Wood
http://wood.jlansford.net/

Otto Yamamoto

2010-02-17 12:45:32 UTC

Post by John Lansford
FHWA won't certify a barrier unless it passes their current level of
crash testing. It may be that they tested it and the barrier did not
perform adequately.

Or it was never tested at all. The documentation is pretty scanty.

--
Otto Yamamoto

John Lansford

2010-02-16 10:36:34 UTC

Post by John F. Carr
Several people have died after being dismembered by pedestrian
handrails in the Big Dig tunnels, according to the Boston Globe.

<http://www.boston.com/news/local/massachusetts/articles/2010/02/14/th...>

sort of off-topic... so if I need to start a new topic.. let me know
does anyone know of any implementation of the NASCAR-style SAFER
barriers anywhere on a public road?

Why? They are designed to keep a 150mph+ vehicle from leaving the
road, and don't take into account such things as maintenance, cost,
big trucks or smaller vehicles.

John Lansford, PE
--
John's Shop of Wood
http://wood.jlansford.net/

MoeNorman

2010-02-16 14:10:46 UTC