A12 road (England)

The A12 is a major road in Eastern England. It runs north-east/south-west between London and the coastal town of Lowestoft in the north-eastern corner of Suffolk, following a similar route to the Great Eastern Main Line until Ipswich. A section of the road between Lowestoft and Great Yarmouth became part of the A47 in 2017. Between the junctions with the M25 and the A14, the A12 forms part of the unsigned Euroroute E30 (prior to 1985, it was the E8). Unlike most A roads, this section of the A12, together with the A14 and the A55, has junction numbers as if it were a The 52 miles (84 km) section of the A12 through Essex has sections of dual two lanes and dual three lanes, with eight changes in width between the M25 to Ipswich. It was named as Britain's worst road because of "potholes and regular closures due to roadworks" in a 2007 survey by Cornhill Insurance. The A12 is covered by the National Highways A12 / A120 route based strategy.

Starting just north of the Blackwall Tunnel, where it connects end on to the A102, it heads north through Bow and Hackney Wick, then north-east through Leyton and Romford, then into Essex, passing Brentwood and Colchester. In Suffolk, it passes Ipswich and Saxmundham, then follows the coast through Lowestoft before entering Norfolk, passing through Gorleston-on-Sea and ending at Great Yarmouth. In February 2017, the route was renumbered between Great Yarmouth and Lowestoft to become the A47. In June 2024, most of the A1117 was renumbered as the A12, incorporating the Lowestoft Gull Wing Bridge, where the A12 now terminates at the A47 in North Lowestoft.