Linear - had not considered that. Just points out the dangers of not knowing the answer before you take the test! But it does say something about range of observational variations being hunched over on your knees on lumpy (1/8" aggregate poking up) masking tape while trying to hold tension.
Been thinking about cal course distances lately and I was wondering if longer cal courses are inherently problematic. It seems to me that the longer a cal course, the more room for error, whether it be tire wobble or not being able to ride the course perfectly straight, or error in setting up the cal course itself, etc.
In my opinion, the most accurate calibration would be 1 count of a Jones counter. Although not practical, if one could measure the distance a tire traveled for 1 count and extrapolate that data to arrive at a constant, that would provide the most accurate calibration data. So, if my theory is correct, wouldn't shorter calibration courses provide more accurate constants? To me it seems that if a measurer has a 100 foot steel tape and lays out a cal course with that, he/she will have less chance of making an error if there is only a single layout of the tape. Multiple layouts of tape (to achieve a 1000' course) are multiple points of potential error. I know there are safeguards in place but a single layout would eliminate the need for those safeguards.
I think that removing potential error points makes for more accurate courses. As far as I can surmise, every extra tape layout, every extra millimeter traveled on a cal course has the potential to affect course (both calibration and race) distance. Not sure if 100' would be the right distance but I do think that cal courses should be less than 1000'. Maybe make 264', 352' or 528' the recommended distance?
I'm probably not the first person to broach this subject but I didn't see anything about it on the forum and I wonder what others that have been doing this a lot longer than me think.
Over 20 years ago, I questioned Carl Agriesti (last measured course shown has a 1983 cert date) about a cal course that started flat and ended up halfway up a hill. His answer was that you are calibrating the rider as much as the bike.
I've also been wondering about the length of cal courses. I have scoured my community and find few places to set up a decent 1000-foot cal course.
The theory is that the biggest source of error in riding calibration courses is the inevitable "wobble" at the beginning of the ride. It's very difficult to ride perfectly straight when you are first start from a standstill. With a very short calibration course this wobble error will make a big difference in the overall calibration count. For longer calibration courses it will make less difference.
When I measured a track with a measuring wheel, I calibrated the wheel with a 100-meter calibration course, because I reasoned there was no "wobble" at the startup. A 20-meter calibration course probably would have worked just as well.
Over the years several people have questioned the 300-meter required length of calibration courses, pointing out the fact as you have, that there are other sources of error that will be bigger for long calibration courses than for short ones. Having to use multiple tape lengths is one, however I tend to think that the small allowable tolerance between the two measurements of the course helps with that one. For me, the more concerning error source is the fact that in some parts of the country it is difficult to find a good location for a 300m calibration course. So people end up locating their course in a location with a slight hill, or where the road isn't perfectly straight, or where the surface isn't typical (concrete instead of asphalt). If they could set up a 100m or 200m cal course they could probably find a better location.
Is the error caused by the above issues bigger or smaller than that caused by startup "wobble?" That's the question.
Here are some threads from years past addressing this issue.
https://measure.infopop.cc/top...-calibration-courses
https://measure.infopop.cc/top...s-unnecessarily-long
https://measure.infopop.cc/top...ation-over-25-meters
I also had a thread reporting results of an experiment I did with 3 different cal courses (100m, 200m, 300m) in the same location. I did multiple rides of each one and compared the cal constants. Unfortunately, I can't find that thread.
Considering most of us wobble a bit when we begin a road course measurement, wouldn't this tend to simply replicate or approximate that which we experience during a calibration ride?
No, because you don't stop and restart every 300 meters when you ride the race course.
I took a measurement seminar from Pete Riegel in 1996 and do remember him saying that we needn't worry about a bit of wobble as it doesn't make much difference.
Obviously, you haven't measured in downtown Baltimore without police escorts, Mark 
.
Actually, I recently re-measured part of the Baltimore Marathon to accommodate a new course configuration requirement. For the first time for several measurements, the City provided me with 4 "motors" and one cruiser. A large portion of the downtown area was briefly closed to traffic as I measured there. These police escorts did a fabulous job. I was able to get through the 11-mile section in a fraction of the time it took when I measured here with no escort.
I agree with Pete and Paul. Unless our wobble is somehow more than the expected slight back-and-forth of our front wheel at the start of pedaling, it seems to me this should make little difference.