On this subject, I had a call from a man named Joe Stallings in 1990, and answered it with a letter. The letter appeared in Measurement News #43, September 1990. You can look it up at:
http://www.runscore.com/coursemeasurement/The cycling people have made a few overtures over the years, but so far, to my knowledge, no measurement standard has resulted.
Given the accuracy of Google Earth, and the tendency of cycling courses to be longer than running courses, it could be that use of Google Earth would be worth exploring.