From the South and North: From I-495, take exit 35 onto Route 3 South. Follow to Exit 29 (Route 129) towards Chelmsford. At the end of the exit ramp, turn left onto Route 129. Proceed through two traffic lights. Approximately .5 miles, where the road begins to narrow, take a left onto Alpha Road. Thermo Fisher Scientific is the last building on the left. From the Boston Area / Logan International Airport: Follow I-93 North to I-95 South (formerly Route 128). Continue to Exit 32A for Route 3 North. Continue to Exit 29 for Route 129 to Chelmsford. At the end of the exit ramp, turn right onto Route 129. Proceed through three traffic lights. Approximately .6 miles, where the road begins to narrow, take a left onto Alpha Road. Thermo Fisher Scientific is the last building on the left.