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By Kevin Flynn
Inside-Lane.com

Interstate 70 reopened to traffic around 3 p.m. Thursday for the first time in four days through Glenwood Canyon, with CDOT clearing one lane in each direction through the area damaged by a rockslide early Monday morning.

The Colorado Department of Transportation imposed a 14-foot limit on vehicle widths during the temporary two-lane restriction. That is because of curvature and narrowed lanes that will be in place until the bridge deck, damaged by numerous boulders including one weighing 66 tons, can be fully repaired over the next few months.

It also temporarily lowered the speed limit to 40 mph.

“CDOT wants to thank motorists and impacted communities for their patience during this time. More information to come tomorrow afternoon on repair plans,” the department said in a statement announcing the reopening.

The emergency started early Monday morning, just after midnight Sunday, when large rocks came down onto the I-70 viaduct west of the ramps to and from the Hanging Lake Rest Area. The slide punctured about a half dozen holes and divots in the bridge deck. At this location, the highway is up against the north wall of the canyon but is elevated on a the viaduct as it curves eastward toward the twin portals of Hanging Lake Tunnels across the Colorado River on the south side of the canyon.

The highway crosses the Colorado River and Union Pacific Railroad, just west of the Shoshone Dam. The debris was scattered over about a 300-foot length of highway.

Traffic moves on I-70 through the rockslide area in Glenwood Canyon Thursday afternoon, after a four-day closure. CDOT photo.

The lengthy closure was made longer by the discovery that another huge boulder, 20 feet in diameter, was perched precariously on the north canyon wall in the slide chute. That made it necessary for CDOT to get the boulder removed and scale off the rest of the loose rock.

That was done Wednesday around sunset, and it worked well for CDOT. The blast not only broke up the boulder into smaller rocks of insufficient mass to inflict more damage on the bridge deck below; it also brought down almost all of the remaining loose rock CDOT had to remove, eliminating the need for extensive follow-up on picking and scaling the canyon wall.

Gov. Bill Ritter declared the situation a disaster on Monday, allowing the state to go after assistance from the Federal Highway Administration to help pay for repairs.

It is close to the same area where an early morning Thanksgiving rockslide in 2004 did much the same type of damage. Then, CDOT was able to get two lanes of traffic reopened in 31 hours but it had to restrict long trailer trucks for two months while full repairs were made and all four lanes reopened.

In this case, the bridge deck damage was more significant and extends into the eastbound lanes, making it more difficult to use them as a detour. CDOT plans to use emergency contracting to hire a company to make the full repairs.