Virginia has contracted with CH2M HILL Constructors Inc. of Denver to add a 5-mile-long truck-climbing lane to southbound Interstate 81 between Ironto and Christiansburg for $75.4 million.

The company, which has an office in Chantilly, will design the expansion, handle land acquisition, easements and utility relocations, and build the new lane, according to a July 14 decision of the Commonwealth Transportation Board that was announced today.

The project will add a third, 12-foot-wide southbound lane in a 65-mph stretch that currently has two southbound lanes, heavy truck traffic and lots of ups and downs over mountains “to improve safety and operation on the interstate," the Virginia Department of Transportation said.

Wider inside and outside shoulders will be built.

During construction, which is scheduled in the spring, the speed limit will likely be reduced to 55 mph and crews may erect a barrier wall -- meaning the outside shoulder will be unusable. If that happens, there will be gaps in the barrier wall for stopping and a wrecker kept on call. Mobile cameras will scan the construction zone.
 
The state expects the new lane to be completed in fall 2013.