To get from Trenton Mercer Airport to your destination: Taxi cabs are usually outside the passenger terminal, if not, call one of the taxi number listed near the public phones inside the terminal.
For directions go get to the Airport from parts of New Jersey, New York City, Philadelphia or Valley Forge /King of Prussia /Norristown areas - open: www.nj.gov/counties/mercer/departments/airport/directions.html

West Trenton Station can be reached by taxi within 5-7 mins,  where you can catch the SEPTA train (open: septa.org) to downtown Philadelphia - a 1-hour ride.  
At Trenton Transit Center you can take the NJ Transit to midtown Manhattan, or use the NJ Transit Link:

New Jersey Transit (NJT) connects the Trenton Train Station to New York City (about $16). For rates & schedules visit: njtransit.com or call NJT at 973-275-5555.
SEPTA -The Southeastern Pennsylvania Transportation Authority - connects Trenton & West Trenton to city center in Philadelphia (about $11). For current rates & schedules visit:  septa.org/welcome or  SEPTA at 215-580-7800.

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