there's people on here from new brunswick, right ?
im sure someone would let you crash with them

it's not quite halfway between the two cities though...
27 is a nice road

also, you could legally camp by the river at washington's crossing state park outside of trenton...
my map also shows 'princeton battelfield state park' and 'cook national area' alongside 27 near princeton...

what is your proposed route ?
this looks like a cool trip