Crews are nearing completion of a detour on a busy commuter route between Jackson, Wyo., and eastern Idaho, where a section of the Teton Pass Freeway collapsed on June 8. Officials hope to have the detour paved and open to traffic this week, Bob says. Hammond, resident engineer with WYDOT.
Evans Construction, based in Jackson, Wyo., is finishing work on the underground and will soon begin transporting the crushed base. The paving work will take another day or two. “It’s quite exciting [to be at this point so quickly]Hammond says.
“I’m very impressed with how quickly Evans responded and collaborated with us on the design,” says Hammond. “They understand the importance of this route to the essential workers who travel it every day.”
The highway is a lifeline for commuters, deliveries, access to medical care and tourism in the region, especially with limited alternatives and the start of the summer season.
The new detour will feature a paved, two-way roadway with two 12-foot lanes. It will also have concrete barriers that protect motorists from any hazards, WYDOT says. The diversion has been built inside the curve of the existing track, away from the zone of unstable sliding. The detour will create a slightly steeper curve and steeper grade than before, and WYDOT plans to reduce speeds through the area to accommodate the grade and increased curvature.
“Through all our knowledge and experience, we believe this temporary road is in a safe place,” says Hammond.
Evans is supplying the project with the crushed base and is also the paving contractor, so availability of labor and materials has not been an issue for the project and helped with the quick response, Hammond says.
The contractor had moved quickly on June 7 to repair a crack and dip in the road near mile marker 12.8 on SH-22 at Teton Pass. Under an emergency contract for WYDOT, Evans worked through the night to remove asphalt from the roadway to minimize weight on the unstable ground. Despite their efforts, the road was dropping about 6 inches per hour, says Craig Clarke, construction manager and vice president of Evans Construction.
“When we realized it was getting dark and we couldn’t go on, we called it off for the night,” says Clarke. Crews moved the construction vehicles to a safe distance and headed home. In the early morning hours of June 8, the causeway failed, “leaving a large cavern with a head escarpment of about 50 straight vertical feet,” Clarke says.
No crew members were injured and no equipment was damaged.
Hammond says Evans’ crews have done “an excellent job with compaction” and is confident the road is safe. WYDOT has begun the process of working toward a permanent solution in a couple of months.
Gov. Mark Gordon issued an executive order declaring an emergency in response to both the landslide at Mile 12.8 and an unrelated mudslide discovered June 7 at Mile 15. The declaration helped the ‘state to quickly access additional resources from the Federal Highway Administration to begin the substantial repairs needed. .
WYDOT was aware of the potential for slides along the freeway and had been regularly monitoring the road, especially since spring runoff had increased erosion, Hammond says.
Built in 1969, the nearly 17-mile stretch of highway is regularly monitored for slides, says WYDOT spokeswoman Stephanie Harsha. “We have a couple of known slide paths in the area, so our geology team goes out there periodically to survey those areas … especially with warming temperatures that cause the snow to melt,” he says.
Yellowstone National Park and Grand Teton National Park remain open to visitors. WYDOT spokesman Doug McGee says traffic along Teton Pass averages about 12,257 vehicles a day this time of year, heading into the parks’ peak season. “This figure is expected to rise to 15,146 vehicles per day in June and surpass July with more than 16,400 vehicles per day,” he adds.
