The crash happened around 9:30 a.m. in the southbound lanes near the on-ramp to Market Street.
Police say the truck driver lost control and smashed through the jersey barriers and went into the northbound lanes.
Another vehicle was involved, police said, but details were not immediately available.
There is no word on if anyone was hurt.
Southbound Route 1 was closed from Perry Street to the Route 1 toll bridge.