Traveling from Philadelphia International Airport (PHL)
Philadelphia International Airport is about two hours from Princeton when traveling by public transportation and one hour by car, assuming no delays.
You would take an "Airport Line" train to 30th Street Station in Center City Philadelphia and transfer to a "Trenton Line" train to Trenton, New Jersey. Upon arrival in Trenton, you would take a New Jersey Transit train to the “Princeton Junction” station.
SEPTA schedules can be found here.
New Jersey Transit Trains
New Jersey Transit train schedules can be found here.
You should select the "Northeast Corridor" Rail Line Schedule to find information on trains to Princeton.
Upon arrival at the New Jersey Transit “Princeton Junction” train station, you may take a taxi (at a cost of about $20 USD) or you may take the New Jersey Transit shuttle train (sometimes referred to as the "DINKY") from the "Princeton Junction" station to the "Princeton" station, and then you may walk to the Institute.