RRTC position on GPS used by runners

Any statement on what position runners wearing GPS should take prior to receiving response from course measurer about "inaccuracies" in their measurement?

I would say the runner should resolve to try hard to follow the SPR as Gene explained. Usually this is very hard to do in a race but easier if you run fast enough to be ahead of most of the field, or either slow enough to be by yourself with a good view of what's ahead. Run right next to the curb on turns, and really straight lines to targets ahead of you. This would give you the best chance to get a close measure.

I generally ask to examine their device, then ask them to bend over so I can store it in a location where it won't get damaged by sunlight.

That hiding the GPS device approach seems a bit harsh. The new USATF/RRTC statement is a much better and more educational way to handle this. Some GPS users are really very nice people and will certainly help to spread the word. The RRTC is now ahead of this problem in an extremely positive way.

I agree 100% Kevin. Around here it seems like the word has already spread a bit. I don't think race directors are hearing from GPS wearers as much as they used to.

The statement is good.
In the past year or two I've provided race directors an information sheet which compares "typical-GPS-user-protocol" to the USATF/RRTC course measurement protocol.

There are days I want to provide counsel along the lines of Keith's "How to Protect Your Consumer-Grade GPS Unit From Needless Sun Exposure," but in many cases we might be the only exposure to the national governing body many runners have. A professional, courteous response can only help our work.

The most important thing is to be positive with folks and their comments about a course being long as their GPS states. I suggest to all to include the statement on your map.

I like the statement, and I agree that we do want to speak in a positive manner (despite what we might be thinking at times)!

But that's a lot of words to go on a map, there's a challenge!

I like this statement. It should help get the word out about GPS vs. certification measurement.

Just for nitpicking (I know, everyone's an amateur editor, right?), I recommend slightly different wording for greater clarity- something like this:

GPS devices work by receiving signals from satellites. The quality of different GPS units can vary, but all of them can be affected by conditions such as buildings in urban environments or heavy overhead tree cover that usually interfere with reception of the satellite signals. Such interference will cause GPS readings to be inaccurate.

Race courses are measured along the "SPR" -- the Shortest Possible Route that a runner can possibly run within the boundaries of the defined course path. Most runners don't actually run the SPR, so the distance recorded by their GPS device will usually be longer than the certified length of the course.

USATF certified race courses are measured by a proven accurate method. This method calibrates each measuring device for each measurement against a steel tape. Multiple measurements under a strict protocol then ensure verification of the course distance.

I am thinking of including this on my next course map somewhere, in a small font, if there is room:

"USATF certified race courses are measured by a proven accurate method. Multiple measurements under a strict protocol ensure verification of the course distance. GPS devices worn by race participants seldom measure accurately, typically overstating the certified course distance."

"Comments, questions, polite insults accepted."

Lyman,
I think it's a bad idea for measurers to start putting their own statements regarding the accuracy of GPS devices, or statements about anything other than descriptions of the course, on their maps. Maps are approved by the USATF, so it would give the impression that the statement is also approved by USATF. If you want to include a statement about GPS on your maps it should match the official USATF statement.
But personally, I don't think we should put anything on our maps about GPS. It makes us look defensive and like we're trying to head off any discussion about it. I'm happy to talk to people about GPS because it often leads to a discussion of the USATF measurement process. The more people who learn about that the better.

Mark, good point about us being defensive. Hence, I say as you stated to just refer to the position if one asks.

It was really nice to read the “USATF/RRTC Position on GPS used by runners” posted at the USATF Face Book page. The post has received a number of comments: https://www.facebook.com/USATFfans

The position is also posted at the Course Certification page: http://www.usatf.org/Products-...-Use-by-Runners.aspx

Mark, upon reflection, I agree.