NORWALK — Interstate 95 was closed northbound between exits 16 and 17 Thursday night into Friday morning because of a crash.

The Connecticut Department of Transportation said the crash involved two vehicles about 9:30 p.m. on the northbound side of the highway, and that traffic was congested back to Exit 14, 2.6 miles.

Motorists were advised by Norwalk police to avoid I-95.

Traffic was heavy northbound, with many trucks, on Route 1 and other secondary roads in Norwalk into Westport.

The DOT initially estimated it would take about an hour to clear the crash scene, but the northbound closure went on past midnight Friday.