START (gr357167) on southbound a1170 at 3rd. kerb joint north of brick pier marked "thundridge" approx. 50 yds. south of hotel entrance. proceed south on a1170 and at first rab take 1st. exit to join slip road onto a10 northbound. continue to puckeridge south rab (junction with a120) where:- turn (4.52 miles) by taking 4th. exit and retrace on a10 southbound. continue past exits for ware (a1170), ware (a602), hertford (a414) and hoddesdon (a1170) to leave a10 at slip road to turnford elevated rab and:- turn (16.94 miles) by taking 3rd. exit to rejoin a10 northbound. retrace past exits for hoddesdon (a1170), harlow (a414), hertford (a414), ware (a602), ware (a1170) and continue to puckeridge south rab where:- turn (29.36 miles) by taking 4th. exit and retrace on a10 southbound. continue past exits for ware (a1170), ware (a602), hertford (a414) and hoddesdon (a1170) to leave a10 at slip road to turnford elevated rab where:- turn (41.78 miles) by taking 3rd. exit to rejoin a10 northbound. retrace past exits for hoddesdon (a1170), harlow (a414), hertford (a414), ware (a602) to leave a10 at slip road to ware & thundridge (a1170). take 1st. exit at rab to:- finish (gr355164) on southbound a1170 at 1st. kerb joint north of cats eye at end of armco barrier and approx. 16yds. past lp474.