COURSE MEASUREMENT

by Ken Kaiser

first published in May 1998 Striders News

In the last newsletter, various points were raised regarding how courses are measured, so I thought I would pass on what information I have.

A couple of years ago after doing several races where I had a good moan about the dodgy mile markers, I read an article in one of the running mags about course measurement, at the end of which there was an appeal for more people to train as approved measurers. In true Yosser Hughes style, I thought "I can do that! Gizza job" and shortly went on a training weekend at Lancaster University to become duly qualified as a North of England AAA course measurer (Grade 2).

The only acceptable means of measurement for road races is by Jones Counter. This is not a measuring device however. It fits on the front wheel of a bike and resembles the pre-electronic mileometers many of us had as kids with a row of 5 numbers. Every revolution of the wheel registers 20 counts. To translate this into distance it is necessary to calibrate the device and in order to do this an accurately measured course is needed. This should be a straight, level section of road. It is possible to measure a course using a surveyors steel (not Nylon) tape, correcting for temperature and keeping the tape under the correct tension, but this is incredibly tedious and a far more convenient method is Electronic Distance Measurement (EDM) as used by surveyors. This, I am told, is incredibly accurate (3cm/km) and such a measured course exists in Leeds on Skeltons Lane, Whinmoor and is used by myself and Colin Morath, the other measurer in Leeds.

So now you have an accurately measured kilometre (or half-mile) you can ride your bike along it and record the counts per 'k'. This is repeated for at least four rides, two in each direction and the average taken. Then a short course prevention factor is added by multiplying by 1.001. This adds 1 metre per 'k' to the course, so a 10k will be 10 metres long and a marathon will be 42 metres long. The final figure is your working constant. This is greatly affected by temperature and tyre pressure, and a further calibration is needed after measuring the course to see if the constant has altered. If it has, the greater measurement is taken. Many of these inaccuracies can be avoided by using (as I do) a solid front tyre, which gives much more consistent readings. It is still necessary to calibrate before every course measuring session.

Having obtained your constant, the proposed course is ridden and adjusted as required. It is a common misunderstanding that courses are measured 1 metre from the kerb on the left side of the road. Courses are measured where the measurer thinks the runners will run, so that means tight to the left on left hand bends and cutting corners to the right, particularly on minor country roads. It should not be possible to run shorter than the measured route, except for blatant deviations from the course.

Which brings us to track races, a whole new kettle of fish. Track measurements are taken 30cm from the kerb on the inside lane and 20cm from the lane marking elsewhere. There is no short course prevention factor involved as measurements can be much more easily standardised in the construction of the track. At a recent major event where several course measurers were present, they were asked to measure the track and all did so using road race technique, hugging the kerb on the bends. By doing this, a distance of up to two metres per lap short on a standard track is recorded, but still legal because the same applies to all tracks. This presumably accounts for the confusion in Max's race, not knowing how far to run.

The other point raised was about road race records. Road courses vary tremendously and for this very reason marathon times are referred to as World Best times not world records. It has also been suggested that separate times should be kept for circular courses, point to point courses and out and back courses. Point to point courses in particular may have an overall fall in height (e.g. Boston, GNR) and may also take advantage of a following wind.

There can be no standardisation of road records because of the wide variety of courses. Finishing time is the only reasonable guide there can be. Even such variations as adding two minutes for Spen 20 is very arbitrary (and regional!). It is up to the runners to pick the courses that they know will suit them or are known to produce fast times. This does not necessarily mean flat e.g. Wakefield 10k.

P.S. from Max: In statistics-mad USA, there are separate records for point-to-point and "loop" courses.

Ken Kaiser is a second-claim member of Valley Striders. His first claim is Horsforth Harriers.


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Created by Bob Jackson eMail bob.jackson@virgin.net
Created on 23 June 1998