Route up to Ithaca NY

This is what you do.....81 north to Harrisburg,Pa 11/15 north to just north of Selinsgrove,Pa 15 and 11 will split, take 11 north along the river,(this will bypass all the stop and go on 15 fron Selinsgrove to Williamsport) over the bridge and turn left at 147 north (once you turn left at 147 you have no more traffic lights until 13 north in NY) that will turn into I 180 west take that into Williamsport, PA and reconnect with 15 north. Once you get on I 180 WEST it is all good 4 lane nonstop to Corning, NY. Take I 86 east at Painted Post, NY to Horseheads, NY and pick up 13 n to Ithaca.
I 81 n
11/15 n
11 n
147 n
I180 w
15 n
I 86 e
13 n