Some folks in my area are planning to conduct a marathon to be run on a high school track. What is our current approach to certifying such an event? (Do you actually need to certify it?) Is it sufficient to check the measurements of the track and then specify the distance to be run on the final partial lap?
Let's say the track does not use an inside rail. I assume we will figure the distance around the track at a distance of 30 cm from the inside (left) edge of the inside lane.
Since this is a track, not a road race, I think we do not need to add a SCPF.
I would welcome corrections, comments, etc.
Original Post

If there is not a curb but only a painted line on the innermost lane, shouldn't the distance from that line be 20 cm? The 30 cm is from a curb.

Pete Riegel has written, some time ago, about how to measure a track.
Bob Baumel wrote on this subject in Measurement News #111, as follows:
Thanks Alan and Pete for refreshing me on that, I guess I knew it was 20 cm in this case but just did a mind-flip or something. I am still wondering if the actual marathon race should receive a certification.
Some high school tracks may not be very accurate. Plus, you may not know if it was surveyed to have a curb( or not). Therefore I would suggest that the course be measured as if it were a road course using the bike method.

Use cones (only really needed on the turns) and measure 30 cm out.

It should be noted that with track measurements, you should measure 30 cm out if there is a curb but only 20 cm out if there is no curb. Cones are not a replacement for a curb and should be placed on the inner white line if a track if it was not measured for a curb.

But with road measuring, we do not differentiate between curbs and cones!
I don't think the approximate method shown above should be acceptable for certifying a course that will be run entirely on the track. It assumes circular curves. If you're going to assume circular curves you might as well just assume the track is 400 meters. And what are you going to do if the measurement comes out to 402 meters? Will you believe it? If you call it 400 in that case and it really is 402, then you'll be certifying a marathon that is 210 meters long.

Using a steel tape to measure a 100 meter cal course on the track and then using a calibrated wheel to measure the track twice probably doesn't take any more time than the 3 steel tapings of the approximate method.

I think the approximate method is ok when the track is just a small part of the course, but not when it is the entire course.
A question came up recently regarding a local New England track. The original survey certificate, sureveyor or striper could no longer be located. Dr. Wayne Armbrust suggested the following:

If the plans are not available, then one should try to reconstruct the original measurements. For the track itself, one can use the procedures outlined on my website at

http://www.computomarx.com/Manual.htm#SEC3

To locate the radius of the inside lane line (or curb) and the distance between radius points. One can then compute the lap length using the formula

L = 2(d + (pi)xr), where d is the distance between radius points, r is the measure line radius, and pi equals 3.14159...

Remember that the measure line is 20 cm from the outside edge of the inside lane line if there is no raised curb or 30 cm from the outside edge of the curb if one is present. If the lap length determined by this method computes out to within a few centimeters of 400m, one can assume the main track is measured correctly.

Wayne's procedure may give some insight on what is involved for certifing a track for track records.

Thank you. -- Justin
Last edited by justinkuo
This is some interesting territory-- the difference between cones, curbs and just plain lines. Recently there was an advisory to allow for the 30 cm additional radius from the line of cones when laying out race-walk courses with wide turns. But I think I'd go with the longstanding track rule-- 20 cm if no curb, even if cones are used to keep runners on the track.
Last edited by bobthurston
The "no curb" track rule = 20 cm does not apply to road races. Measure 30 cm from curbs or cones.
This is the way international race walk courses are measured....which I just happen to be measuring the Olympic race walk course this coming Wednesday morning (August 1).
We couldn't do it in June because of construction left on the course from the Queens Jubilee.
Wow. Hope you'll give us another colorful account!
Not sure I understand about the 20 cm, aren't we supposed to measure within 20 cm if there is no curb?