Wellingborough, The A509 is a short A-class road (around 30 miles (48 km) long) for north–south journeys in south central England, forming the route from Kettering in Northamptonshire to the A5 in Milton Keynes, via M1 junction 14.

After this it goes on to form the Wellingborough western bypass before leaving Northamptonshire to cross into the City of Milton Keynes (and Buckinghamshire).

Here the A509 is a single carriageway once more until it crosses the M1 at junction 14, where it enters the Milton Keynes urban area.

[1] A bid for Major Road Network funding was submitted to the Department for Transport (DfT)in March 2020, with a Strategic Outline Business Case in December 2020.

In October 2021, £1.9 million of funding from the DfT was secured towards the next stages of developing the proposals for the bypass.