The Utah Department of Transportation is installing a new temporary bridge to carry Interstate 80 traffic over Union Pacific railroad tracks in western Salt Lake County during a construction project. The state Department of Transportation says the temporary bridge in sections that crews are assembling next to eastbound I-80 at the junction with State Route 201 will be used while crews demolish and reconstruct the existing bridges. The department says it’s using a construction method called ”launching.” That method involves having bulldozers push assembled sections of temporary bridge out over the train tracks to rest on supports already constructed.