It is the start of the 2017 Cross Country season! And no start is official until some sort of discussion creeps in about course measurement. So here it is! Advance warning though that this article is not intended to be argumentative ("quit using GPS and stop measuring down the middle") or give a "how to" approach for course measurement (see an excellent 2010 review at http://fl.milesplit.com/articles/52762/best-practices-for-cross-country-course-measurement). This is hopefully something new and practical to consider regarding Cross Country course measurement.
But first, here is a little back story to the article. A couple of things happened last year that caused me to take a deeper look and consideration of course measurement and data comparison. It was not a large leap for me. I am a Licensed Professional Surveyor and Mapper. Accurate data representation, high precision measurement, and mapping are kind of in my wheelhouse.
Short Course
The first "issue" was that I casually measured three (3) courses back in 2015, at a friend's request, with my rugged 15.5" diameter Keson Measuring Wheel (standard $150 wheel most all of the coaches typically use) and found all three courses to be considerably short of 5000 meters. When the coaches asked me what my measurement of their course was, they were not happy with my answer. That concerned and bothered me. So I measured them again. Same answer. I almost lost a few good friends.
As a Professional Surveyor and Mapper I understand that the measuring wheel is not the most accurate piece of equipment for all-terrain measurement especially on rough and undulating surfaces. But most all of our cross country courses are measured with them. That caused me to wonder how far off could the measuring wheel be. And if it was off, could there be a general "calibrated constant" for various surfaces to be considered and applied? These questions sent me off on a quest for "wheel measurement enlightenment". What I found out surprised me.
Data Comparison
The second thing that happened which caused me to search for deeper answers was that mid-way through the Track and Field season many of the Cross Country courses from the previous season got re-classified from 5000 Meters to 3 Miles. At first I was not happy. These fast times are sacred to my runners and to my own coaching pride. So I headed on another "quest for understanding", this time, in data comparison. I have to be honest here. The more I studied and compared results from the "short" courses with State Meet results, courses I trusted as accurate, and conversions and comparisons of track and field times, a different picture and perspective began to emerge. Not perfect, just different. Could this be a useable "measuring" tool" to flesh out short courses?
I heard a college coach once say that time results from a cross country race are influenced by four considerations: (1) accuracy of the course; (2) terrain of the course; (3) level of competition; and (4) weather. Each year, in Florida, the fastest times consistently seem to come from meets like FSU Pre-State and FLrunners, where all four of those factors are often heightened. APR is an accurate course that has a general net downhill, has excellent fast terrain, great competition, and typically cool weather. FLrunners is similarly fast. When a large number of runners race faster in other races, against lesser competition, under warmer conditions, on tougher terrain, the results are going to be suspect. Certainly there can be outliers (sometimes you just have one of those awesome days where everything aligns or the course is predominately asphalt), but when I looked hard at the data (Milesplit has a great tool for comparing races) for our runners with the races removed, it gave me a more realistic and honest season result and outlook. That is one of the reasons why I believe the accuracy of course measurement has value and importance. Our kids today seem to thinks so. It is a rare team and program that can just focus upon championships. Most of our kids today just want to run a fast 5K on a course they can trust. I think we can do better with consistent course measurements from what I learned through the following field study.
Course Measurement Field Test
As a Surveyor I became intrigued with the idea of establishing a baseline range for comparative measurements on a variety of terrains and surfaces that typically comprise a cross country course. I found a unique area that had a 750 foot (229m) straightaway. Along this tangent section there were 5 different surface areas of asphalt, concrete, long grass (1-1 1/2"), short grass (1/2"), and a hard compacted dirt pathway adjacent and parallel to the baseline.
I established starting and end points exactly 750.00 feet (229m) in length in each of the 5 surfaces areas that were measured with both a steel measuring tape and with a laser measurement survey theodolite (sub cm. accuracy) instrument. Following the establishment of each baseline, I wheeled each surface 7 times forward and backward. Here is the averaged result of my wheel measured field test.
Surface Wheel Measure Difference 5000m Diff Factor
Asphalt 750' 0' 0' 1.0000
Concrete 750' 0' 0' 1.0000
Short Grass 745' 5' 109.36' 1.0067
High Grass 743' 7' 153.10' 1.0093
Compacted Dirt 743' 7' 153.10' 1.0093
Going into the Field Test I anticipated measurements in excess of 750 feet measured by the wheel. The majority of discussions I read about in course measurements seemed to focus in on "wobble factors", "catching air", and "rolling up and over undulating surfaces". All of my measurements on these five common Florida surfaces for Cross Country were short of 750 feet leaving me with this consideration. The single greatest factor to consider when measuring a cross country course with a wheel is SLIPPAGE. The rubber surface on the measuring wheel slips and slides (small but repetitively consistent) on grass and dirt even with the best of care and effort but not on the harder surfaces of asphalt and concrete.
With that new finding, here is where my mind immediately raced to consider. For those that are concerned about a predominately grass course that might measure 165 feet (50 meters) short, it is probably not that short and could be a lot closer to 5000 meters than one thinks. Conversely, for those that work so hard to wheel measure their courses along the shortest path a runner could run and consistently check and re-check to make sure it measures 16,404 feet (5000 meters) might be producing courses that could actually be long.
Let me also add that there are still some other factors to consider that I also looked at in subsequent measurement tests that should be considered when measuring courses and establishing baselines. Wet grass had a higher "slippage" factor than dry and was slightly more inconsistent (7-10' on short grass per 750 feet). Loose dirt had even larger under values (10-13 feet per 750 feet). Also, after I completed my research, I found another similar study that was done in 2007 by former Washington and Lee Cross Country Coach John Tucker. His work showed similar results and can be viewed at http://oncourseratingsystems.com/Images/whyOCRS.pdf.
A 5000 Meter Cross Country Course Test Case
Recently I had the opportunity to measure the new Holy Trinity Academy Cross Country course in Melbourne. Coach Scott Baker had recently modified the course and had expressed how he had spent considerable time and effort measuring the course with both a wheel and then with a measuring tape (his wheeled measured distance came up shorter than the tape measure). He was confident in its 5000 meter steel tape measured length. When I measured the course I initially came out with a wheeled measurement of 16,326 feet, coming up 78 feet (23 meters) short of the 16,404 feet (5000m) standard course measurement. BUT, what happens when you factor in wheel "SLIPPAGE" on the grass surface. From our previous survey baseline test, we found that on short grass surfaces which was consistent with the Holy Trinity course, we had a slippage factor of 1.0067 (5' short for every 750'). The Course had 5,032 feet of asphalt, concrete, and rubber track surface (which is a lot but has a 0 slippage factor) and 11,294 feet of short grass (with a slippage factor of 1.0067). When the slippage factor for grass surface is applied (11,294 x 1.0067) and added to the 5,032 feet of asphalt, concrete, and track surface you come up with a total "real" measurement of 16,402 feet. That is impressively close to 5000 meters (16,404 feet).
On a side note, hopefully by now, we have all thrown out the idea (and use) of GPS watches in course measurement. Steel Tape Measurement IS THE MOST ACCURATE means to measure a cross country course. But it is time consuming and generally takes a minimum of 2-3 people and 3-4 hours of time to complete every year unless you have a permanent course. It is also probably not feasible to hire a survey crew to measure your course (they are not cheap, trust me).
Conclusion
Most likely, no runner is ever going to run exactly 5000 meters in a cross country race. Equally unlikely is that we will ever measure a perfect 5000 meter course (too many factors). But we can do better and hopefully eliminate "re-classified" race courses. Our sport could benefit by reasonably objective result comparisons through courses that are accurate. Proper course measurement is important to our kids who want their performances to have consistent meaning. I would like to encourage coaches and race managers to consider two things with your courses this season: (1) please re-read Jason's article on "Best Practices for Cross Country Course Measurement" linked above and (2) consider measuring your course with a steel measuring tape or creating an accurate measured baseline and calibrate your wheel over the various terrain surfaces that make up your course. Then apply those calibrated constants to your measurements to come up with the best, most accurate and realistic 5000 meter cross country course.
Mark Caulfield has been a Florida Licensed Surveyor and Mapper for 27 years and is also the Boys and Girls Cross Country and Track & Field Coach at Circle Christian School in Orlando. For questions or more information, he can be reached at markc@circlechristianschool.org.