M25 motorway the east of Gravesend and Grays, the Lower Thames Crossing, in order to relieve congestion on the A282 Dartford Crossing and connect the M25 at North Ockendon in Essex with the M2 in Kent. At Junction 5, the clockwise carriageway of the M25 is routed off the main north–south dual carriageway onto the main east–west dual carriageway with the main north–south carriageway becoming the A21. In the opposite direction, to the east of the point where the M25 diverges from the main east–west carriageway, that carriageway become the M26 motorway. The radial distance from London (taken as Charing Cross) varies
London Borough of Croydon is linked into the national motorway network via the M23 and M25 orbital motorway. The M25 skirts the south of the borough, linking Croydon with other parts of London and the surrounding counties; the M23 branches from the M25 close to Coulsdon, linking the town with the south coast, Crawley, Reigate, and Gatwick Airport. The A23 connects the borough with the motorways. The A23 is the major trunk road through Croydon, linking it with central London, East Sussex, Horsham, and Littlehaven. The old London to Brighton road, passes through the west of the borough on Purley Way, bypassing the commercial