Originally it started on the A6 in the centre of Barton-le-Clay, Bedfordshire. However, the village having now been bypassed, and the B655 having taken over the entire pre-bypass A6 through Barton, the B655 now has a pair of western starting-points: one at a roundabout at the northern end of the bypass, and the other at a south-facing GSJ at its southern end. Bedford Road (from the north) and Luton Road (from the south) meet head-on on immediately south of the village centre, and from here the B655 sets off eastward along Hexton Road. The built-up area quickly left behind, our route runs along the edge of the Barton Hills, climbing as it does so.
The county boundary does some strange things in this area. We pass through Hexton, Herts, and then Pegsdon, Beds, before entering Hertfordshire for good on reaching the top of the ridge and crossing the Icknield Way. The road then descends again and soon reaches the outskirts of Hitchin and ends at a mini-roundabout on the A505 to the west of the town centre.
An amended OpenStreetMap trace for this route awaits uploading to the SABRE Wiki.