**An Article from Team San Angelo email Newsletter**

*by Bill Cullins*

**Certifying a Running Course**

Most of the top running events are held on "certified" courses, meaning that the course distance has been accurately measured as per procedures approved by USA Track and Field. I recently had the pleasure of conducting the rigorous measurement process as we obtained a certification for the 2007 Run in the Sun 8K course, and I now have a much greater appreciation for what "certified" means. Like most runners and cyclists, I had always assumed that an automobile odometer, bike computer, or a hand held GPS unit was fairly accurate.

To measure a course as per USATF standards, the first step is to measure a “calibration" course. This has to be at least 300 meters but can be longer. In our case, we used fixed endpoints for the calibration course (two fire hydrants) and so ended up with a 354 meter calibrations distance. This calibration course had to be measured with a steel tape, stretched with exactly a set amount of force, and then adjusted for thermal expansion.

After laying out the calibration course, the next step was to install and program a USATF-approved bike computer. The USATF measurement committee prefers that a traditional mechanical device (Jones counter) be used, but the certification process does allow for the use of a bike computer (electronic counter) if specific guidelines are followed and if an approved computer is used (Protege 9.0 recommended). The biggest difference in the application of the bike computer is that it isn't used to directly measure miles or kilometers; instead, it is programmed to measure "counts", which are revolutions of the bike wheel. The bike rim is also marked so as to allow partial wheel revolutions to be measured. In my case, I marked the rim into 40 equidistant increments which allowed a measurement accuracy of 1/40th of a wheel revolution.

After setting up the calibration course and bike computer, etc. the next step was to ride the calibration course four consecutive times and then average the readings. Remember that the data collected was full and partial "counts" (wheel revolutions), so at the end of the calibration course rides we could divide the number of counts by the calibration course length to calculate what is called the "working constant", or counts/meter. This preliminary working constant was then multiplied by 1.001 ("short course prevention factor") to get the real working constant. In the case of our calibration course, this resulted in .4798 counts per meter. This working constant number was then used to predict where the 4K (4000 meter) turn around point and the mile split points would be. For example, .4798 counts/meter times 4000 meters equaled 1,919 counts plus 2/10 of a count (8 of the 40 rim divisions).

After (finally!) getting the target values for the turn point and mile splits, the next step was to do a measurement ride of the actual and place preliminary marks at all critical locations. Since the major reasons for certifying a course are to (1) make sure the distance is accurate and (2) insure that the course measurement can be validated in case a record is established, the actual course ride had to follow the shortest path for the route. That meant that the measurement ride had to follow the tangents; i.e., straightening out the curves as much as possible. I can assure that riding the exact tangents is a fun exercise in concentration while on River Road with traffic. The target values (previously calculated) were used to place preliminary split and tam around marks on the course.

A second (and 3rd, and 4th, ...) measurement ride was then done to insure that the initial preliminary marks were accurately placed and could be replicated. The amount of allowable variance between measurements could not exceed 8/100 of one percent. My repeat measurements resulted in a difference of 6/100 of a percent(notmuch - about 15 feet over the entire 8K distance). The course turn point was then adjusted to reflect the difference between the measurements to insure that the final distance was at least 8K.

After doing the initial calibration course and measurement rides, it was back to the calibration course (same day) for four more passes over the 354 meter distance. Again, the golden standard was to document that pre and post measurements along this calibration distance were within a set margin of error. If the numbers had too much variance, it was back to square one and start the process over. Unfortunately, I made a number of rookie measuring person mistakes and ended up repeating the complete process several times with long distance guidance from Pete Riegel, a national USATF measurement guru. The last step was to complete a ream of paperwork that documented the entire process and all of the measurements and calculations. A detailed course map with explicit descriptions for the start, turn, and each split mark location had to be prepared. It all paid off in the end, however, and we now have Certification Measurement Certificate # TX07012PR for the 2007 Run in the Sun course.