The B8020 provides a back-road link between the Villages of Broxburn, Winchburgh, and Woodend in West Lothian. The road was originally unclassified but had gained its number by 1932.
The route begins at a T-junction on the A899 in Broxburn town centre and heads north, arrow-straight out of the town centre, and past an important industrial area before heading past some traditional terraced mining houses. Leaving Broxburn the speed limit rises to 40 mph and the route encounters the first of several 90° bends. As it turns it heads directly towards a huge steep sided pit bing (spoil tip) – a legacy of the area's mining past – and the speed limit rises to NSL. Another couple of right angle bends allows the road to skirt the bing and soon the limit drops to 30 mph as it enters the outskirts of Winchburgh. Here yet another 90° bend on a junction takes it over the Union Canal via a narrow bridge. The road then passes typical 1960s-build council housing as it heads up towards a T-Junction with the B9080 (former A9).
Turning right onto a multiplex with the B9080 the road runs through the Victorian town centre and passes more mining cottage terraces. Just after passing the old Victorian-era primary school it turns left and leaves the B9080 behind. The limit soon rises back to NSL and the road heads arrow-straight once more under two bridges, one carrying the main Edinburgh to Glasgow railway line and the other the M9. In 2021, legal orders were published for the construction of a new interchange (Winchburgh Junction) to be constructed with the M9 at this point.
Beyond the bridges the route follows a series of tight narrow bends around Duntarvie Castle, a couple of which are made all the more challenging by having junctions on them. Leaving these behind, the limit drops to 30 as the road enters the final and smallest village, Woodend. Here, after a short distance, it reaches the end at a T-junction with the A904. This junction has been reprofiled, with the A904 realigned to avoid a nasty double bend and the B8020 extended to meet it.