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Wyoming’s New Approach to Highway Crash Cushioning

September 29, 2020
teton pass
CrashGard sand barrels act as a crash cushion along the Teton Pass in Wyoming.

Wyoming is known for its striking, rugged landscape and the highways that wind through it. The state is a tourist destination in the summer and winter months, and Highway 22, also known as Teton Pass because of the mountain range it traverses, can be a challenge, both for drivers inexperienced with the area and for vehicles towing trailers. Brake failure is not uncommon, which is why runaway truck ramps are placed along the length of the road. These afford drivers an opportunity to bring their vehicles safely to a stop while avoiding potentially catastrophic collisions.

“Teton Pass is heavily traveled. During peak periods, we see 15,000 vehicles a day,” says Darin Kaufman, District Traffic Engineer with the Wyoming Department of Transportation (WYDOT). That’s a lot for this fairly remote area, and of course, the greater the traffic load, the higher the chance for a brake failure incident.

A Change of Plan

WYDOT’s prior approach to runaway vehicle mitigation was a catchnet system that Kaufman describes as a construct of cable and energy-absorbing canisters. Although the catchnet system had been successful—it had stopped six runaway vehicles on the pass since 2017—an incident in 2019 resulted in a vehicle plowing all the way through to the end of catchnet array.

Because summer season and the restriction on trailers was being lifted soon, WYDOT needed to act quickly, they opted to search for a temporary solution—the CrashGard® sand barrel system by PSS –. “CrashGard is a non-redirective system that can be easily placed to keep drivers safe and protect highway assets,” says Jordan McMullen, New Products & Channels Coordinator at PSS. 

teton pass barrels
Traffic safety measures are paramount in the Teton Pass area, which is heavily trafficked by tourists that may not know the route well.

The barrels act as a crash cushion. One standard MASH-compliant* barrel can be configured to contain anywhere from 200 to 2,100 pounds of sand. Each barrel comes standard with a lid and an insert. For barrels of less than maximum capacity, the insert is placed at a specific height above the bottom of the barrel and the desired volume of sand is then poured on top of it. The barrels can be filled onsite or, as WYDOT chose to do, at an offsite location and then trailered in for placement with the CrashGard hoist

“We knew that since we have a history of runaway trucks, we needed to do something quickly. We couldn’t ignore the history of incidents. We reached out to multiple vendors, but TAPCO, a CrashGard distributor, was the only one that could do the job,” says Kaufman. “Others didn’t have the resources to meet our needs.” 

The Setup

In a CrashGard array, barrels in the front of the grouping contain less sand, with the weight increasing in increments the further back the barrels sit. This allows them to gradually slow and stop a vehicle, resulting in less overall damage and the reduced likelihood of driver injury.

“For our application, we used five groupings of barrels arranged in a total of 39 rows, with a concrete barrier on either side. The total length of the array was about 180 feet from first barrel to last,” says Kaufman. “We worked with the Midwest Roadside Safety Facility out of the University of Nebraska and the manufacturer to model the system and get it configured properly. Once we had an approved design, it only took two or three days to install it.” 

teton pass
The high-density polyethylene barrels can be recycled and take just one day to reinstall when damaged.

The finished system is engineered to stop a 60,000-pound vehicle going at 60 mph. In the event of an incident, Kaufman reports it only takes the WYDOT maintenance team a day to reinstall the damaged barrels, and many of them can be reused. “We’ve been very satisfied,” says Kaufman. “It was very easy working with TAPCO and we felt quite comfortable installing the system since it had passed the MASH requirement of 12 g-force units.”  It should be noted that the crashgard is a temporary installment, it has not been properly field tested, only ran in models on the computer.  With that in mind WYDOT initiated a mandatory brake check at the top of the pass and reduced the posted truck speed to 45mph, until the catchnet system is replaced.

McMullen adds, “It’s an economical alternative to catchnet systems, which are expensive. The entire CrashGard system consists of identical barrels that each include a lid and an insert, with all three parts purchased as a single unit. Due to the insert, only one size barrel is needed, regardless of the amount of sand to be placed inside. This prevents DOTs from having to purchase barrels of different sizes or needing to buy each of the components separately.”

The system tends to hold up well upon impact, often with only a few barrels being damaged after a crash. Because they are made of 100 percent high-density polyethylene, those that are destroyed can be recycled, says McMullen.

Unique Challenges

Because the Teton Pass area is heavily trafficked by tourists, many people travel the road who aren’t familiar with the steep grade of the highway and its curves. “We have national parks—Grand Teton and Yellowstone—and snow skiing in the winter,” says Kaufman. “We draw people from all over the world—some of whom are familiar with the route, and some who aren’t. For those who aren’t, the terrain can catch them off-guard,” says Kaufman. 

Even those truckers familiar with it, however, may find it reassuring that should their brakes fail on the pass, WYDOT has them covered.

*MASH-compliant refers to the Manual for Assessing Safety Hardware published by the American Association of Highway and Transportation Officials; it is the standard for highway crash testing.

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