The A508 is a short A-class road for north/south journeys in south central England, forming the route from Market Harborough in Leicestershire, via Northampton, to Old Stratford, just outside Milton Keynes.
The road begins in the centre of Market Harborough and crosses into Northamptonshire just outside the town. Crossing the A14 at Kelmarsh, it continues on through the centre of Northampton, merging with the A5199 as it enters the town. Through Northampton the road repeatedly switches between being a dual carriageway and a single carriageway.
From there, it merges briefly with the A45 until it crosses the M1 at junction 15. Resuming its identity, it continues through Roade, Grafton Regis and rural south Northamptonshire, reaching the A5 and the A422 at Old Stratford, a Northamptonshire village which adjoins Milton Keynes.
Between Market Harborough and Northampton, travelling south, there are two fixed (Gatso) speed cameras. The first is on top of the A14 junction (40 mph (64 km/h) limit) and the second is approx 0.5 miles (0.80 km) from the village of Lamport (60 mph (97 km/h) limit). Both of these cameras are rotated, meaning that they face the opposite direction of travel every so often. There is a further speed camera just south of junction 15 and another in Roade. The majority of the stretch between Northampton and Milton Keynes is national speed limit (60 mph (97 km/h)), although there are 30 mph (48 km/h) limits in Roade and Grafton Regis.