It’s surprising that the question of elevation error was not recognized long ago, but here we are. We have a conflict between what we can do and what the “drop” rule requires.
With regard to course length, we instituted the Short Course Prevention Factor, which is easily applied by the measurer when the course is laid out. It provides reasonable assurance that the course is not short of its nominal length. Validations have shown that it works.
With regard to elevations, the only practical tool we have is published elevation data. This has historically been obtained from topographical maps, and lately through the use of Google Earth and other online tools which allow estimation of elevation data. Now we are belatedly aware that the error in the elevation data may create problems in determining whether course drop exceeds the limit. What can we do about it?
A level survey conducted between start and finish can provide a closer estimate of the difference than can examination of maps and online sources. It is highly unlikely that anyone would seriously consider doing this, as it can be time-consuming, expensive, and outside the competence range of anyone except a professional surveyor. I don’t consider it a reasonable tool, and think that making it a requirement is not a smart thing to do.
So where are we? We lay out a course with a route specified by a race director. We add the SCPF, and when we look at the end points we estimate their elevations. In the vast number of courses these elevations are of little interest to anyone, as records are quite rare.
In spite of the error ranges which have been discussed it remains a fact that the elevations obtained by maps or Google Earth represent the most probably correct values, if one must pick a single value.
I see this as a problem for the USATF Records Committee, and I would recommend that they accept images of maps or screen shots of Google Earth as absolutely correct. There is no practical alternative that I can see. As far as I know elevations have been taken at face value as long as road records have been kept by USATF.
In short, I recommend that nothing be done.
The thing that started this discussion was an inquiry by David Katz, who was concerned that a course had a drop very close to the limit, and who was concerned that validation might find the course drop over the limit. He considered a record to be somewhat probable given the quality of the field. In this case I’d recommend that he arm himself with documentation that supports the claim that drop is within the limits, and that the Records Committee accept this at face value.