It happened around 1:00 p.m. Saturday afternoon at the Ferry Avenue station.
DRPA officials say the officer was sitting in his car, when a man approached, appearing to ask a question.
When the officer rolled down his window, the suspect punched him in the eye and fled.
The officer was taken to an area hospital for treatment and is expected to be okay.
Authorities say it does not appear that the suspect and officer knew each other.
The suspect has not yet been apprehended. Police continue to investigate.