From j1 of the M3 continue on the A316 towards central London. At the 3rd junction take the 4th exit (heading south) on the A312 Uxbridge Rd to Hampton. Pass Sainsburys to mini roundabout and turn left on A313, Park Rd, straight over traffic lights into Hampton Rd, 1km pass Teddington Memorial Hospital on right and at next traffic lights turn right into B358 Queens Rd. The entrance to NPL is aprox 0.3km on the right opposite Park Lane