The New York, Susquehanna & Western Railway maintenance will continue Thursday in Sparta.
The project, which began Wednesday at 6 p.m., will continue through the night and into Thursday until about noon and detours will be established at Houses Corner Road for traffic heading Route 15 south, said department spokesman Sgt. John-Paul Beebe.
Beebe said northbound traffic will not be detoured and warned that drivers should expect heavy delays as the project progresses.
Motorists are urged to take alternate routes or allow for a considerable amount of additional time in which to reach their respective destinations, he added.