We take great pride in creating courses for our runners that capture the best of the local scenery and provide a safe race experience. This does not come without some serious and labor-intensive behind-the-scenes logistics though, course measurement is precise down to inches – yes, every single inch counts. Moving a curb in the road 10 inches can affect the course (and actually has).
2021 Eversource Hartford Marathon, Half Marathon and 5K courses are all USA Track & Field Certified courses. Courses are not measured by GPS, tape measure, surveying equipment, car, or by walking with a measuring wheel. All certified road race courses are measured by a standard bicycle fitted with a calibrated mechanical counter on the front wheel. We hire a certified certifier (they really exist, we can’t make this stuff up!) who follows a 100-page manual of rules.
We often get asked by participants why their GPS readings are not the same as course length. Typically, the "short course prevention factor" throws off the measurement. All USATF certified courses are required to include a 1/10th of 1 percent (one-thousandth percent) extra cushion to make sure no one runs less than the stated distance. For a full marathon, that means 42.1925 extra meters or a little more than 135 feet. This is standard to every single certified course, so give yourself a little extra credit!
When you train with a GPS, you stop when you hit the mileage you need for that run - whether 12 miles or 20, your GPS indicates when you need to stop. When you run certified courses, especially courses with as many turns as the 2021 courses have, it is common for you to run further than 26.2 or 13.1. Zig-zagging through people and running wide on turns by even a little adds up to tenths of miles here and there. Typically, only the people in the very front of the race are able to run the certified distance as they can see the straightest lines to run without people ahead of them (and don't need to weave through anyone).
You’ll note the language on course certificates confirms that measurements are taken “along the shortest possible route within the road and path pavement”. Most people do not naturally run the tangents along roads, which is also how courses are measured longer on personal GPS devices.