HOW ARE COURSES MEASURED?
The UKA requires courses to be measured according to IAAF procedures by a measurer who is accredited for measurement in the UK.
The measurer will ride a bicycle along the shortest possible route, within the boundaries of the course. He uses a special counter to record the revolutions of the front wheel which gives a precision of about 10 cm. To get an accurate length he has to calibrate his bicycle by riding along a short calibration course which has been accurately surveyed with a steel tape or an Electronic Distance Measuring machine.
The overall accuracy of measurement is normally a little better than 1 part in 1000, which is equivalent to 10 metres in a 10K or 42 meters in a marathon. To ensure the course is at least the advertised distance, the measurer uses a short course prevention factor when determining the official distance. For example, he will aim to make a 10,000 metre course 10,010 metres long, and the official distance which appears on the certificate will be 10,000 metres, because the measurement has established that the course is definitely not less than 10,000 metres.