start on b1043, approx. 300 yards north of tempsford flyover, 195 yards north of lamp-post 21 and 5 yards north of the 7th drain north of lamp-post 21. [this is the3rd drain south of gateway and 100 yards south of kerb start.] (gr163527)proceed south, straight on at 1st mini-rab to join a1 (care) and continue over sandy rab to:-turn (5.16 miles) at north biggleswade rab (warden lane), retrace a1 northbound, continue over sandy rab to:- FINISH by bearing left off the A1 at Blunham Lane to finish at Clearway end sign (GR162522).