For the 1920 Isle of Man TT, changes were made to the Mountain Course and competitors turned left at Cronk-ny-Mona and followed the primary A18 Mountain Road to Governor's Bridge with a new start/finish line on Glencrutchery Road which lengthened the course from the pre-World War I length of to . An extensive programme of road improvements occurred to many roads in 1922 by the Highway Board including the Mountain Course with road widening at Sulby Bridge, from Port-e-Chee on the A1 Peel Road to Braddan Bridge and part of the main road through Crosby. Modification of Signpost Corner including rounding off the bend occurred in 1922 along with further road widening at Governor's Bridge with the completion of the link road to A2 Glencrutchery Road/Governor's Road and the removal of fence posts at Keppel Gate. Further changes to the course followed in 1922 with the adoption of a private road part of the Ballastowle Estate between Parliament Square and May Hill in Ramsey. The course had previously had negotiated the A2 Albert Road and Tower Road in Ramsey and the new course length was now . The official course distance for the Snaefell Mountain Course was amended in 1938 to which is the current course length.