START (GR 513297) at 7th kerb joint from northern end of lay-by south of 34th milestone on the B1383. Proceed north through Quendon, Newport, Roundabout at junction with B1052, Littlebury, Great Chesterford, to Stump Cross roundabout (9.83m). Turn left at 1st exit onto A1301 to cross straight over next two roundabouts, whilst passing under A11 flyover, to the Hinxton Hall roundabout where straight on to the Sawston roundabout at the junction with the A505. Turn (12.25m) to retrace to pass under the A11 to Stump Cross roundabout. Turn right , 2nd exit, onto B1383 and retrace along course to FINISH (GR 512289) at surface water gully at centre of green just north of "Chequers" PH.