|From:||Shepherd's Bush (TQ237798)|
|Length:||13.7 miles (22 km)|
|Meets:||A402, A219, B408, A4000, A406, B455, B452, A4001, A3002, A4127, A3005, A312, B465, A437, B483, A408, A4007, B467, M40, A40, A412|
|Route outline (key)|
The A4020 follows the original route of the A40 before the latter was diverted along its current course via Western Avenue.
The A402 takes the original line of the A40 from Marble Arch to Shepherd's Bush. Just west of the A3220 West Cross Route, that road reaches Shepherd's Bush Green where it forks left, with the A4020 taking the right fork and the old A40. In reality, Shepherd's Bush Green is a gyratory and so westbound A4020 traffic and eastbound A402 traffic has to use the third side of the triangle, which is part of the A219 mainline (albeit still one-way).
The A4020 extricates itself from the gyratory at its northwest corner and heads west along Uxbridge Road, a place it won't get to for some time yet. It goes under the Hammersmith & City Line at Shepherd's Bush Market station and continues along a straight road, lined with shops and partially residential. Presently the road goes under the North London Line to reach Acton. It goes along the traffic-calmed High Street to a roundabout by Morrisons where the A4000 turns right. The A4020 is the dominant number in a short multiplex with that road turning left at the next set of traffic lights.
Back on Uxbridge Road again the A4020 skirts Twyford Gardens before passing Ealing Common tube station to cross Ealing Common itself. The A406 is crossed at traffic lights before the Common is left behind and the road runs along The Broadway in Ealing (Ealing Broadway station is just to the north). The road continues on through the suburbs of Ealing and skirts Hanwell Cemetery. In the centre of Hanwell the A4001 turns left at traffic lights, then the A3002 comes in from the left at the next set; these two roads are part of the same one-way system. The River Brent is crossed immediately afterwards leading on to a dual carriageway. The road is even wide enough for there to be two lanes in each direction not including the bus lanes.
The road narrows to pass under the Great Western Main Line; this is also a staggered crossroads where we meet the A4127 so it can get a bit busy. The road becomes D2 again on the far side before narrowing once more as we pass Southall Park to enter Southall. We run along the High Street, then back onto Uxbridge Road and become dual again after crossing the Grand Union Canal. A few hundred yards further on we reach a roundabout GSJ on the A312 (we're the road that has to give way).
The road remains dual as it passes to the north of Hayes to reach Hillingdon, where the road is the dominant partner in a multiplex with the A437. The road then bends to the right past a golf course to head due north to a roundabout on the edge of Uxbridge town centre. The road to the right, the B483, is the best way to get back to the A40; ahead is the High Street which is the original line of the road but now pedestrianised; to continue on the A4020 we turn left.
We skirt the southern edge of the town centre to reach a gyratory where we meet the A408 and A4007. Turning right, we head north to a roundabout then rejoin the original line of the A4020 just before the road narrows to cross the Grand Union Canal and then the River Colne. Grass is now visible behind the hedge on the left; this is the closest we get to being rural as the road always has buildings on at least one side. Passing through the suburb of New Denham we pass a garden centre and then reach an NSL sign. It doesn't last very long, however, as we get to a roundabout immediately afterwards where the road ends. This is one of the roundabouts at Denham Roundabout, also known as M40 J1, where we finally rejoin the A40.