start in the lay-by on the a15 approximately 0.5 mile south of the b1206 (redbourne junction). proceed north on the a15 to the a15/m180 interchange (4.934 miles). encircle the roundabout and follow the a15 south to turn left onto the b1206 signposted redbourne (9.526 miles) to finish at a gap in the hedge 4.5 yards short of a marked tree.