Take exit 37B to merge onto I-95 South/RT-128 South towards Waltham.
Go about 7 miles, then take Exit 31B towards Bedford. Continue with directions below.
From Cambridge/Harvard University
Follow Mass Ave. northbound or Fresh Pond Parkway (Route 16E) to Route 2 West.
Head west on Route 2 towards Concord for 6.2 miles.
Take Exit 52B to merge onto Route 128/I-95 North towards Peabody.
Go for 3.5 miles, then take Exit 31B towards Bedford. Continue with directions below.
From Exit 31B
At the top of the exit ramp, reset your trip odometer.
Follow Route 4/225 (this is called The Great Rd) through Bedford Center for about 3 miles.Stay on Route 225 for exactly one mile.At 3.9 miles keep your eyes peeled for the small blue street sign on the right side of the road that says "Old Causeway Rd".
Go through six stoplights at 0.6 miles, 1.2 miles, 1.5 miles, 1.9 miles, 2.1 miles and 2.4 miles.
At 2.7 miles, stay to the right to remain on Route 4/225; avoid Route 62 which splits off to the left.
At 2.8 miles (across from the Volkswagon dealership) get in the left turn lane and make an odd little left turn onto Route 225 (in front of the gas station).
Turn right onto Old Causeway Road and follow the road through the woods to the Concord Field Station, at about 4.4 miles.
If you miss the blue street sign, you'll know you went too far when you see that you are crossing a river (about half a mile too far down Rt. 225). Turn around, go back and turn left onto Old Causeway Rd.