SOUTH DEERFIELD — The bridge carrying North Main Street over the railroad tracks will be closed to traffic indefinitely as the Massachusetts Department of Transportation (MassDOT) repairs deteriorated decking discovered during scheduled maintenance on Wednesday.

During the closure, traffic coming from the South Deerfield village will be detoured to Hillside Road, while traffic on the northern end of the street will be detoured to Routes 5 and 10 toward North Hillside Road. Drivers are urged to reduce their speed, use caution and expect delays.