17.14 mile circuit used on the 18th and 19th March 1908.
Map showing the two courses used on the 25th and 26th November 1908. The shorter course used for the Light Car race was 9.8 miles long. The longer course was 25.13 miles long.
17.3 mile circuit used during November 1910. The roads were modified for the 1911 races, with the corbers broadened and lengthened, and bad stretches rebuilt. This reduced the length to 17.14 miles.