The man was struck on the Gladstone Branch by train 732 around 1:45 p.m. in Basking Ridge, NJT spokesman Everett Merrill said.
The train had left Summit at 12:14 p.m. and was scheduled to arrive in Gladstone at 2:08 p.m.
The one passenger and crew members were not injured, Merrill said. Service was suspended between Stirling and Bernardsville on the Gladstone branch, with bus service accommodating.
NJT police were leading the investigation.
Click here to follow Daily Voice Elizabeth and receive free news updates.