The Colorado Dept. of Transportation has hired Kraemer North America on a CM/GC contract to lead the emergency repair and rebuild of a critical section of U.S. 36 that buckled earlier this week and temporarily shut down eastbound traffic on the Boulder Turnpike. U.S. 36 is the main artery that connects Boulder and Denver and serves the busy retail and tech corridor on the city’s north side. The state's transportation commission recently approved $20.4 million to fund the repairs and other expenses associated with the bridge collapse.

That section of the freeway is only a little over five years old, part of a major highway renovation project completed in 2013 by a joint venture of Ames and Granite. The U.S. 36 highway expansion was one component of a complex, multi-phase, public-private partnership (P3) agreement between CDOT and a consortium known as Plenary Roads Denver, which now oversees and maintains the highway and its tolled express lanes.

The eastbound lanes of U.S. 36 were closed July 11 after a large crack appeared in the pavement. Officials at the scene speculated that a key bridge spanning a railway about halfway between Denver and Boulder may have been damaged by settling soils after heavy rains in the area during the week, but that has not been determined as the official cause. That section of the highway runs near several wetlands, and the north side of metro area is plagued by the presence of heavy clay content in the soils.

The crack in the roadway developed slowly at first, allowing the agency to close the freeway lanes to traffic before any accidents occurred. But over the weekend, the crack widened, and a large sinkhole appeared as the pavement sunk below grade. An entire section of the bridge had collapsed by Monday and by mid-week, the damaged portion stretched nearly 300 ft long. No one has been hurt or killed, and the cause of the incident remains under investigation.

Thus far, a separate structure carrying the westbound lanes of the freeway has not been adversely affected, and eastbound traffic has been detoured into a compressed-lane configuration using the westbound side. Crews have disconnected the two bridges, and officials are keeping a close eye on the westbound structure for signs of similar stress and fatigue.

CDOT says the contract with Kraemer North America has no anticipated completion date as yet, until the full scope of repairs is known.

The agency’s executive director, Shoshana Lew, said in a statement: “We are pleased to have selected Kraemer so that we can transition to beginning permanent repairs to U.S. 36 eastbound.”

This story was edited on July 19 to include the dollar amount approved by the state's transportation commission for the roadway repairs.