It happened around 3:20 p.m. on Friday.
So far, Amtrak and New Jersey transit customers can expect delays of about 30 minutes to an hour on the Northeast Corridor.
None of the 170 passengers aboard the train were injured.
Trains are operating at restricted speeds through the area with two of the four available tracks open at this time.
Service between Boston and New York and Washington and Philadelphia is not affected.
Passengers are encouraged to call 800-USA-RAIL or visit Amtrak.com for schedule information and train status updates.