|Distance:||1.1 miles (1.7 km)|
|Route outline (key)|
Originally the route started in the centre of Penzance at the junction of Causewayhead (now pedestrianized) and the Greenmarket (B3313, later the extended A30). The western terminus has also shifted slightly: the B3312 originally ended at the eastern entrance to Madron, at the junction with Bellair Road.
The road was declassified in the 1980s but seems to have got its number back around 2010.