Underpass, Chingford Hatch
The A1009 starts on the eastbound onslip to the A406 amongst the Walthamstow Reservoirs at South Chingford. It heads north before turning east at a roundabout. After going through Chingford Hatch it crosses the A104 at a staggered junction before ending on the A113 within sight of the southern end of the M11.
In 1922 it only ran on its Woodford section, between the A11 (current A104) and the A113, albeit along Snakes Lane, to the north of its current route; the road was moved southwards in the 1940s. It was extended west to meet the A406 some time after the North Circular was complete (this section is still marked as A111 in 1932, for example).