London Inner Ring Road

The London Inner Ring Road, or Ring Road as signposted, is a 12-mile (19 km) route with an average diameter of 2.75–5.5 miles (4.43–8.85 km) formed from a number of major roads that encircle Central London.^[1] The ring road forms the boundary of the London congestion charge zone, although the ring road itself is not part of the zone.

Starting at the northernmost point and moving clockwise, the roads defining the boundary are Pentonville Road, City Road, Old Street, Great Eastern Street, Commercial Street, Mansell Street, Tower Bridge, Tower Bridge Road, New Kent Road, the Elephant & Castle, Kennington Lane, the roads that constitute the Vauxhall Cross one-way system and Vauxhall Bridge, Vauxhall Bridge Road, the roads that constitute the Victoria one-way system, Grosvenor Place, Park Lane, Edgware Road, Old Marylebone Road, Marylebone Road and Euston Road.^[2]

The route is described as the "Inner" Ring Road because there are two further sets of roads that have been described as London ring roads. The North and South Circular Roads together form the second ring road around London, averaging 10–15 miles (16–24 km) in diameter. The M25 motorway is the outermost road encircling the metropolis, at an average diameter of 40–50 miles (64–80 km).