Course Measurement and Certification Procedures
The Shortest Possible Route
A race course is defined by the shortest possible route that a runner could take and not be disqualified. A given runner might not follow the shortest possible route, just as a runner on a track may be forced to run further to pass another runner. The actual path of any given runner is irrelevant. The shortest possible route is a reasonably well-defined and unambiguous route that ensures all runners will run at least the stated race distance.
You might envision the shortest possible route as a string, stretched tightly along the course so that it comes within 30 cm (one foot) of all corners, straight through S-turns, and diagonally between corners when crossing a street. You should measure the course following the same route as that hypothetical string.
Because it is difficult to follow the shortest possible route perfectly, an extra length factor of 0.1%, called the short course prevention factor, is incorporated into the calibration procedure. Use of the factor ensures that your course will not be short, even if you make small errors in following the shortest possible route.
When making a turn, measure prudently close to the curb or edge of the roadway. Thirty centimeters (one foot) from the edge of the roadway is a good quide. Often manholes, storm drains, broken pavement, and other hazards render this impractical. In such cases, attempt to measure the shortest route that a runner may be expected to take. You may wish to walk the bicycle through such sections if they are relatively short.
There are three basic situations encountered in following the shortest possible route. First, if you enter a roadway by making a right turn and leave it by making another right turn, follow a path prudently close to the curb around both turns and in-between.
Second, if you enter a roadway by making a right turn and leave it by making a left turn, move in as straight a line as possible, diagonally from where you entered on the right to the most extreme left position available to the runner just before making the second turn. Again, make the second turn as prudently close to the curb as you can. In the case of heavy traffic, you may wish to employ the "offset maneuver" described in Appendix A (Supplementary Tips).
Third, when measuring on a winding roadway, do not follow the side of the road. Unless portions of the roadway will be closed to runners by cones and/or barricades and will be monitored, measure the straightest and shortest path possible, moving from one side of the road to the other as necessary to follow the shortest possible route. This may be an unsafe practice on heavily travelled roads. You may need to measure with a police escort or measure during periods when traffic is light.
When measuring a turn-around point, cycle up to the position of the turn, freeze the front wheel, record the count, reverse the bicycle, and proceed back in the other direction. Do not cycle "wide" around the turn.
The course must be measured as it will be when the race is run. In particular, detouring around cars or other obstacles which may not be present on the day of the race will make the course short (see Supplementary Tips).
If your course is laid out to restrict the runners to a route which is longer than the shortest possible route (on pavement), traffic barricades or intensive coning is required. Course monitors are nice but often are absent, mis-positioned, or simply ignored by the runners. Instruct course monitors to disqualify on the spot, any runners they observe cutting the course as defined by the barricades and cones.
The locations of barriers must be marked on the road, and their exact locations put on the map. You should be prepared to document every such marker that you put in place. If this seems like too much trouble, you should assume that runners will short-cut all they can and measure that way, even if the runners are instructed to run a longer route.
If you restrict the runners to one side of the road, be sure you specify how the corners are to be turned. It makes a difference. There should be no doubt of the exact measured path.
If you cannot enforce the restrictions, it's best to measure the shortest possible route and leave race-day coning as the race director wishes it.
Sometimes the paved route is likely to be ignored by the runners. Plan for this, and measure across the grass in those areas where the runners are likely to shortcut. Be sure the route you choose is bounded by something that is permanent.
Sometimes the sides of the road are poorly defined. For example, the Fiesta Island 10 km has a paved road with firm dirt shoulders that some runners prefer to run on.
Selecting the exact running/measuring route is a matter of judgment. It is probably best to remain on the pavement but as close to the dirt edge as possible unless the dirt route is obviously shorter. In that case, you should measure the shortest route on the dirt.
In summary, study is required to determine the shortest route that can actually be run, whether it be in the street, on the sidewalk, or on the grass or dirt.