North Circular Road

The North Circular Road (officially the A406 and sometimes known as simply the North Circular) is a 25.7-mile-long (41.4 km) ring road around the northern half of inner London. It runs from Chiswick in the west to North Woolwich in the east via suburban north London, connecting various suburbs and other trunk roads in the region.

Together with its counterpart, the South Circular Road, it mostly forms a ring road around inner London, except for crossing of the River Thames, which is done by the Woolwich Ferry.

The road was constructed in the Interwar period to connect local industrial communities and by pass London. It was upgraded after World War II, and was at one point planned to become a motorway as part of the controversial and ultimately cancelled London Ringways scheme. In the early 1990s, the road was extended to bypass Barking and meet the A13 north of Woolwich, though without a direct link to the ferry.

The road's design varies from six-lane dual carriageway to urban streets; the latter, although short, cause traffic congestion in London and are regularly featured on local traffic reports, particularly at Bounds Green. The uncertainty of development has caused urban decay and property blight along its route, and led to criticism over its poor pollution record. Several London Borough Councils have set up regeneration projects to improve the environment for communities close to the road.

The North Circular Road forms the northern part of a ring-road around Central London. It has seen substantially more investment than its counterpart, the South Circular Road, and consequently runs on more purpose-built road than urban streets, often coupled with demolition of existing houses and urban infrastructure. Although the route has alternative names at some points, it is generally referred to as the North Circular throughout for route planning purposes.

The route is mostly grade-separated dual carriageway from the A40 at Hanger Lane to the A13 in Beckton except for the Drury Way/Brentfield Road junction, the Golders Green Road/Brent Street junction, Henlys Corner and the section from Bounds Green to Green Lanes. In areas where improvements made slowest progress and upgrades are unlikely, the original names such as Gunnersbury Avenue and Bowes Road are used.

The road begins in Gunnersbury at the Chiswick flyover (junction 1 of the M4), from which the South Circular Road (A205) heads south over Kew Bridge, and the A4 heads east towards Chiswick and west towards Brentford. The first section runs along Gunnersbury Avenue through Gunnersbury Park to Ealing Common, with a mix of single and dual carriageways, where it becomes Hanger Lane.

The road crosses the Great Western Main Line west of Paddington to the Hanger Lane gyratory system, a large roundabout on top of the Western Avenue (the A40) with Hanger Lane tube station. This is one of the busiest junctions in London, used by 10,000 vehicles an hour.