Course Measurement and Certification Procedures
APPENDIX A - Supplementary Tips
Dealing with Obstacles
When measuring the course, you may encounter an obstacle, such as a parked car, that will not be present on race day. One way to deal with this problem is as follows:
stop your bicycle just before the obstacle
freeze your front wheel with your hand or the brake
very carefully move the bicycle perpendicular to the route being measured until you are clear of the obstacle
release the wheel and proceed until past the obstacle
reverse the process with the wheel frozen to return to the shortest possible route
Use this procedure sparingly and report each instance in your application for certification. If you have to do this more than a few times on the course, try again on another day when most of the obstacles are gone.
Dealing with Traffic (the "Offset Maneuver")
It may not be possible to measure some sections of a road course with reasonable safety at any time. The preferred method is to arrange an "escort," which may be an official police escort or simply a large truck equipped with arrows and blinkers used for traffic control.
If the critical section requires a long diagonal run across traffic, you may wish to consider an "offset maneuver." This is performed as follows:
Measure along the (straight) road edge to where a crosswalk or expansion crack lies. Using this as a guide, physically carry the bicycle across the street with the front wheel frozen. Continue the measurement along the opposite side of the roadway. This errs on the side of making the course very slightly longer but it may save your life. When crossing the roadway, be sure you cross perpendicular to the direction of the roadway.
Two-Cyclist Riding Techique
It is often faster and more enjoyable—and possibly also more reliable—to measure with a second cyclist instead of just doing two rides of the course by yourself. Either way, we use the one set of marks technique. This means that tentative start, finish, and split marks are only painted on the road during the first measurement. In a two-cyclist measurement, only the lead rider paints marks on the road. No new marks are ever painted during the second measurement. Therefore, the second cyclist simply stops at the points already marked by the first cyclist, and records counter readings at exactly those marks. To minimize confusion during this process and subsequent data analysis, the second cyclist should not pre-calculate any counter readings from his/her working constant before riding.
The two cyclists should strive to make their measurements as independent as possible; i.e., each rider should exercise his/her own judgement as to where the shortest possible route lies. The measurements will not be truly independent if the second cyclist follows directly in the tracks of the first cyclist. Ideally, the second cyclist should follow two or three blocks behind the first cyclist; however, this may not be practical in certain situations; e.g., if you have a police escort.
Whenever a course is measured by more than one cyclist, every cyclist who rides the race course must do his or her own pre-measurement and post-measurement calibration rides. A separate copy of the Bicycle Calibration Data Sheet must be completed for each rider, calculating individual riding constants for each rider. This procedure must be followed even when cyclists use the same bicycle, because riding constants will vary for different cyclists, depending on riders’ weights and riding styles.
A course measurer should always wear an orange, reflective, safety vest. A helmet is also an essential piece of safety gear. These will tend to make you look more "official," like a member of a highway crew, and will make you much more visible. Since the route that must be measured is often not the logical route for a cyclist, motorists may not be able to easily predict your direction and avoid you.
Even if you cannot arrange an official police escort, a friend following you in a truck with emergency lights flashing can provide considerable protection when measuring in traffic.
When steel-taping or making permanent marks, you may wish to use safety flags or stop signs to add to the protection of the measuring team.
Minimizing Stops to Check the Counter
Electronic devices are available that attach to the front wheel and provide digital readouts via a display mounted on the handlebars. Although not sufficiently accurate for certification purposes, such devices can alert you to the upcoming location of intermediate split points and measurement end points on your first measurement. Such devices are available in many bicycle stores.
You may also find it convenient to mark (with a felt-tip pen) all your intermediate stop counts on a sheet of folded 8.5x11 paper and fasten this to the front brake cables with clothes pins for easy reference.
Solid Tires and Avoidance of Flats
A flat (front) tire is a disaster! If you get a flat, all measurements made since the last calibration are invalid. You must fix the flat and start over with a new calibration.
Solid tires are one way of avoiding flats. Solid tires require a period of "breaking in," which you should reach after roughly 50 kilometers of riding. Solid tires have two major advantages. First, you eliminate flat tires and the wasted measurements that accompany a flat tire. This allows you to ride the shortest possible route with more confidence since glass fragments are no longer a problem.
Second, the day-to-day and within-day variations in the calibration constant are smaller. Solid tires do not eliminate the need to calibrate before and after measuring, but they do reduce differences between the working and finish constants.
Locating Intermediate Split Points
Many races have signs indicating kilometer or mile points and may have times read to the runners at several points. A "locator" guide describing how to find a painted split point quickly when driving along in a car is often useful. Very little time is available to place signs and drop off timers on race day, and such a guide helps assure the runners will get splits at the proper points. Few things are more frustrating to a serious runner than to realize mid-way through the race that the splits are all wrong!
Measuring at Night
For urban race courses on busy streets, the only time that the traffic density is light enough to permit a proper course measurement may be late at night. If you measure at night, you must calibrate and recalibrate during the same night under the same conditions as the course measurement. Do not calibrate before sunset, measure at night, and then recalibrate after dawn.
You will need a good light system for your bicycle and a flashlight to read the Jones Counter. Many Ni-Cad battery-powered light units are available and work very well. You may also attach a flashing strobe light to your bike or person. These units are cheap, lightweight, and provide a greatly increased degree of safety. Use plenty of reflective material such as a vest and reflectors for your bicycle. Wear a helmet. Do not measure alone at night. Have a car behind you with high beams on.
Do not measure at night unless you know exactly where the shortest possible route lies. Visibility may not be good enough to sight distant corners.
Walking the Bicycle
Walking the bicycle removes weight and reduces the counts required to cover a given distance. If this is done while measuring the race course, it will tend to produce a race course that is slightly oversized (which is acceptable). The portions of the course that a bicycle is walked over will be roughly 1% longer than if the bicycle were ridden.
You may find it necessary to walk the bicycle for short distances near intermediate marks, through large potholes or other paving disasters, and occasionally up hills too steep to ride. You might consider measuring down such hills by making temporary marks at the top and bottom and measuring between them in the reverse direction.
You should never walk the bicycle over any portion of the calibration course since this will tend to produce short courses.
Measuring on Dirt, Grass, and Sand
Avoid laying out a course over non-paved surfaces. If you must, minimize the distance to be measured over such surfaces. Hard-packed dirt is OK, but avoid sand, soft dirt, and deep grass.
The greatest accuracy is obtained by steel-taping all non-paved sections. However, measuring the entire course with a bicycle calibrated on a standard, paved calibration course is acceptable and is, in fact, the recommended procedure since it reduces the chance of error.
The calculations (for start, finish, splits, etc.) can get quite complicated if you piece together a course measured partly by bicycle and partly by steel tape. If you do this, make permanent marks at those points where you change between bicycle and tape measurements.
When you ride the bicycle over non-paved sections, you will tend to get fewer counts than you would riding over the same distance on a paved surface. This will tend to make your course slightly longer. Measuring on firm dirt should not lengthen that part of the course by more than 0.1%; measuring on grass may lengthen that portion by 1% or more; measuring in loose sand may lengthen it by more than 3%.
Measuring dirt roads usually presents little problem if the road is well graded. If the non-paved road is not graded (usually two ruts) and is winding, it may be virtually impossible to ride the shortest possible route since the proper route would cross the ruts and intermediate ridge at angles which do not permit safe riding. If such sections are encountered and cannot be avoided, they must be steel-taped.
Minimizing Temperature Effects
In many locales, the daily temperature range may be 20 °C (36 °F) or more. Such temperature extremes usually create a greater difference between the working and finish (calibration) constants. You can reduce this difference by measuring on days when the temperature variation is small, such as on cloudy days or near dawn when the temperature changes slowly.
Another way to reduce this effect is to make more frequent re-calibration runs. If you measure over a period of five or more hours, you may wish to do a set of calibration rides mid-way through your measuring. This is feasible only if the calibration course is not too far from the race course. It does have the additional advantage that it "protects" at least some of your measurements against flat tires.
Since you might be calibrating before dawn or after dusk, you may wish to make the paint marks on your calibration course with fluorescent paint for better visibility.
As a warning when approaching the end of the calibration course, an arrow 10 meters or so before the marked endpoints can be helpful. Another useful feature is to paint dots every 30 m or 100 ft to be used as reference points while calibrating.
If parked cars are a problem, you can establish the calibration course 2.5 meters from the curb.
As a safety measure, you might want to lay out two calibration courses—one on each side of the street—so that you are always able to ride legally with traffic. Note that each course must be measured and certified separately.