quote:We've been defining a track mile as 5255.26 feet for at least as long. The decision that running around turns is 24.74 feet harder than running straight was somewhat arbitrary, but it was made. If someone does a study that determines it's actually 30 feet harder to run around turns, should we shorten all our tracks? Of course not. Everybody has been running 5255 feet for many decades and we should continue to make them run that same distance. The same is true for the 5285-foot road mile.
Was such a decision made?
Seems to me the decision that was made is that we could measure the length of a track much more accurately than we could measure the length of a road course. Accordingly we don't leave as much slack in our track measurements than we do in our road course measurements.
I'd also challenge the 5255 number. The question is "what part of the body are we measuring?" If one is running counterclockwise around a track, one's left side travels a shorter distance than one's right side does. Parts of us travel 5255 feet or less. Parts of us travel more.
Another bit of information on the Autobahn course: The official PR information about the course states that it is 3.56 miles in length. My SPR measurement showed it to be closer to 3.42 miles. The racing surface is 40 feet wide, and it appears there are about 1800 degrees of curvature on the course I measured. The difference between measuring on the inside of every curve and down the center of the track should be:
6 meters (half the width of the track) x 1800/360 x Pi x 2 = 188.5 meters or 0.117 miles.
This ignores the changes on the straight sections of the course but they tend to be negligible anyway.
I don't know how the owners measured the course, but the above calculations give us some insight on how they might have.