The A406 or the North Circular Road is a trunk-road linking west and east London going via North London.
Its western end starts at junction 2 of the M4 motorway and the South Circular Road. It then goes via Gunnersbury Avenue, crossing Uxbridge Road onto Hanger Lane past Hanger Hill, then crosses Western Avenue and turns north-east and becomes the North Circular Road. It continues past Stonebridge Park railway station, and crosses Harrow Road. It goes through Neasden, then crosses Edgware Road and has a junction with the M1 motorway at Staples Corner. It passes by the Brent Cross Interchange, through Golders Green, then south of Finchley. It goes north of St Pancras and Islington Cemetery, and at Friern Barnet becomes Pinkham Way. It turns right into Bowes Road, becames the North Circular Road again at Green Lane, then Sterling Way after it crosses the Great Cambridge Road. After it crosses Fore Street it becomes Angel Road, then the Lea Valley Viaduct as it crosses the River Lea.
It becomes Southend Road and passes north of Walthamstow, and crosses Woodford New Road at Waterworks Corner. It then leaves Southend Road at an elevated junction with the M11 motorway above Charlie Brown's Roundabout, and starts heading south, passing the Eastern Avenue at Redbridge Roundabout. It passes Romford Road passes east of Ilford. It then crosses Barking Road in Barking, and ends at an interchange with Newham Way in East Ham.