Its western end is at junction 1 of the M4 motorway (Surrey Crescent), where the North Circular Road or A406 ends. From here it heads southwest along Chiswick High Road, then south across Kew Bridge over the Thames. It then crosses Kew Green on Kew Road, joins Mortlake Road, crosses Lower Richmond Road at Chalkers Corner, and joins Clifford Avenue. It then turns sharply east along Upper Richmond Road, passing through East Sheen, Barnes and Putney, then merges with the A3 (on West Hill, Wandsworth High Street, East Hill, Huguenot Place, Wandsworth Common North Side, Battersea Rise) as it passes through Wandsworth. Arriving at Clapham Common, it diverges from the A3 and joins Clapham Common West Side, The Avenue, Cavendish Road, then Poynders Road, Atkins Road and Streatham Place. It crosses the A23 at Streatham Hill, joining Christchurch Road, Norwood Road and then Thurlow Park Road. It passes Dulwich Common and Sydenham Hill (the site of the former Crystal Palace, now replaced by a radio mast), then passes through Forest Hill on Lordship Lane, London Road, Dartmouth Road, Waldram Crescent, Waldram Park Road, Sunderland Road and Stanstead Road. It follows the Catford gyratory system on Catford Road, Sangley Road and Plassy Road, leaving Catford on Brownhill Road. It then passes through Lee on St. Mildred's Road, joining Westhorne Avenue in Eltham as it crosses the A20 at the Cliftons roundabout, the A210 at the Yorkshire Grey roundabout, the A2 at an unnamed junction, and the ancient Rochester Way at Well Hall roundabout. It then turns north and climbs Shooter's Hill on Well Hall Road, and descends the hill on Academy Road, past Woolwich Naval Academy, crossing Woolwich Common, following Woolwich New Road and Grand Depot Road. It then forks, one branch following John Wilson Street which terminates near the Woolwich Ferry pier on the River Thames, the other branch continuing into Woolwich on New Road and terminating at the riverside.