The Gran Premio Canal de Castilla covers four types of surface in addition to conventional tarmac (which still makes up over 50% of the route).
Each of the sections where one of these other types of paving is used is known as “SPECIAL SECTION”.
For each type of special section a core colour is used on the route maps and the signs which indicate the start of each section. The colours used are yellow for the towpaths, light brown for the strade bianche (white gravel paths), burgundy for urban paving, red for cobblestones and grey for conventional tarmac.
The Gran Premio Canal de Castilla project would be the longest International Cycling (UCI) race with more than 85km (50 miles) on non-conventional surfaces.
Translation: Jeanette Hodgman (email@example.com)