The B531 is a largely residential B-road in Bedford.
The route starts by Bedford Hospital at traffic lights where the A5141TOTSOs. It heads southwest along Kempston Road and soon goes over the Midland Main Line. We're now in Kempston, and the road name changes to Bedford Road.
The castellated TA centre is passed after which the road skirts Addison Howard Park before becoming lined with shops. By Lidl there is a mini-roundabout where the B560 continues ahead whilst we turn left, although until completion of the western bypass the B531 ended here on what was the A5134. St John's Street is now followed to a full-size roundabout where we bear right onto Woburn Road. We continue south-westward through the suburbs, passing the HQ of Bedfordshire Police before we arrive in an industrial estate. The road runs alongside the A421 southern bypass for a couple of roundabouts before ending at the large Marsh Leys Roundabout, part of a GSJ where we meets the A6 (formerly A428) western bypass.