A $13 billion plan to revamp Interstate 81 has come to the end of the road. Houston-based KBR Inc. has withdrawn from the public-private partnership handling the project, effectively killing it. Nonetheless, the commonwealth will continue scaled-down efforts to improve the highway.

KBR was the lead company in Star Solutions, a consortium of seven companies that had been selected to add tolls and extra lanes to the 325 miles of I-81 running through Virginia. The highway, a major transportation route in the Shenandoah Valley and Southwest Virginia, has seen traffic triple during the past 20 years.

KBR separated from its parent company, Halliburton Inc., and became publicly traded last year. KBR officials sent a letter to David S. Ekern, commissioner of the Virginia Department of Transportation (VDOT), saying that the I-81 project no longer fit its business profile. “This change does not slow down the planned safety improvements on I-81,” Ekern said in a statement. “It will just change the method through which we deliver these projects.”

Ekern has ordered VDOT to stop any activity related to the public-private partnership, but it is moving forward with truck-climbing lanes in Rockbridge and Montgomery counties. VDOT will spend $146 million on those projects and award them through conventional bidding.

Robin Sullenberger, CEO of the Shenandoah Valley Partnership, says that he does not consider the end of the Star Solutions plan to be a significant setback. “I don’t think most people in the Valley ever expected it to come to total fruition anyway,” he says “Our objective now is to make sure that the process continues so that long-term improvements to I-81 continue to be made, even if they’re incremental.”

Without private investment, VDOT does not have the money to undertake a comprehensive improvement plan but does have $730 million set aside for spot-improvement projects to I-81 during the next six years.