Studies under way at Nichols Consulting Engineers of Reno could one day help extend northern Nevada's short construction season as well as allow local general contractors to haul loads of asphalt much greater distances when paving the state's rural roadways.Nichols in late August won a $446,002 contract to design an experiment studying warm mix asphalt for the Federal Highway Administration's Long-Term Pavement Performance program. The company has been involved in transportation research since 1990, says Kevin Senn, a principal engineer who has been with the firm since graduating from Washington State University in 1995.Long-Term Pavement Performance program started in the …