Route 2 eastbound in Bozrah is closed between exits 23 and 27 after a tractor-trailer struck a man.
State police said a man had gotten out of his car and was getting back into the vehicle when he was struck.
LifeStar medical helicopter transported the man to a hospital in Providence, Rhode Island, where he is in serious condition.
The road is expected to remain closed until at least 9:30 a.m. Traffic is being detoured onto State Highway 608.
