|Distance:||8 miles (12.9 km)|
|Meets:||A408, A4, M4, B376, B3021, B3022|
|Route outline (key)|
The B470 is a medium-length B-road in the Home Counties. Given its location it is surprisingly rural.
It starts at a set of traffic lights on the A408 in Cowley, to the south of Uxbridge. It heads west along Iver Lane and soon crosses Fray's River, the Grand Union Canal and the River Colne in quick succession. After crossing a bridge over the M25 it goes through Iver before slowly bending to head southwards.
After crossing the Grand Union Canal again it enters the Slough urban area. It crosses the Great Western Main Line by Langley station before making its way through the suburb of Langley and reaching the A4, which it meets at traffic lights.
Originally the B470 ended here. However, it has now been extended along most of the route of the A331 which was presumably downgraded to keep through traffic out of Windsor.
The B470, therefore, multiplexes east along the A4 to the next roundabout, which is junction 5 of the M4. It regains its number and runs southwest, along a new alignment parallel to the motorway (the old A331 started opposite the B470 in Langley but its route was severed by the M4). After passing the Queen Mother Reservoir there is a left turn signposted as the B376. However, this is only a spur of that road - or maybe its number is not set in stone as the signs at the other end claim it to be a spur of the B470.
Over half a mile further on the mainline of the B376 is met in the centre of Datchet. There is a short multiplex between two mini-roundabouts on the village green before the B470 continues south and soon crosses a level crossing by Datchet station on the Windsor to Staines line. Almost immediately afterwards there is a T-junction on the bank of the River Thames. The B470 TOTSOs right here (the road left is the B3021) and follows the river for about half a mile before crossing it. The B470 skirts the grounds of Windsor Castle before passing the Riverside station before ending at a set of traffic lights. The only other classified road here is the B3022 which continues up to Windsor High Street but the reason for the unusual classification here is because the pedestrianised road to the right, over Windsor Bridge, was the original through route until it was closed to traffic. The B3022 still reappears on the other side of the river although there is no easy way for vehicles to get from one to the other.