The northbound lanes have been reopened on the Hutchinson River Parkway at the Kings Street overpass, near the New York/Connecticut state line.
The parkway had been closed earlier when a tractor-trailer slammed into the overpass.
Police say the truck hit the King Street overpass at the New York/Connecticut state line around 11:45 a.m.
The truck was carrying heavy metal columns, some of which were blocking the roadway. The columns, which weigh about 4,000 pounds each, are for lights at an athletic field. Heavy equipment was needed to remove the poles from the truck and the parkway.
The truck was on the parkway illegally as all commercial vehicles are banned from NY parkways.