Paxman wrote:
Official road races are measured using a calibrated bicycle with a mechanical counter on a wheel
Calibrated is the key. Tire size and pressure will influence a tire circumference, so a measuring wheel is probably the best bet in this case. It's only a mile so that's not too far to walk. You can pick up a wheel from Lowes for 50 bucks or borrow one from a local coach or excavator. Don't use the ones with the tiny wheel. Get the big wheel style.
Measure and cut a 110 yard piece of string.
Tie a rock to each end.
Lay it down 16 times end over end, marking a quarter mile every 4 times.
huh?
An Jones counter is the best.
Failing that get an old style regular cycle computer (not gps) and carefully calibrate the wheel circumference. This can be done by putting a paint mark on a tyre and then riding for a short distance, then carefully measure the distance between paint marks with a tape measure.
Car odometres and gps devices are unlikely to be as accurate. A good measuring wheel will be reasonably accurate, but it's slow if the course you're measuring is long.
Electronic distance measurement devices can be used for distances up to 5 kilometers, and they offer accuracies of up to 1 part in 20,000. The primary advantage of using EDM devices for land survey measurements is the speed and accuracy with which they deliver readings.
There are three primary types of commonly used surveyor instruments for EDM:
Microwave instruments – These instruments use microwaves to take survey measurements. They have a range up to 100 km and are comprised of two identical units, a master unit, and a remote unit.
Infrared wave instruments – This type of instrument uses amplitude modulated infrared waves and prism reflectors. They have a range up to 3 km and accuracy of +/- 10mm.
Light wave instruments – These instruments rely on the propagation of modulated light waves. Their accuracy varies from 0.5mm to 5mm/km, and they have a daytime range of 3km and night range of 2.5km.
https://www.baselineequipment.com/land-surveying-accurate-distance-measuring
I put an odometer accurate to 3 digits on my bike.
Went to a track. Hand rotated the wheel until the digit clicked.
Walked it back and forth on the 100 meter straightaway on a track 16 times,
plus an extra 10 meters.
Noted how many wheel revolutions it took past the last digit click to get to the exact mile.
Then I walked the dirt road by my house.
You could also measure out a known distance on a rope/wire and mark off your route.
(ie: 100 foot marked on a rope laid out 52 times plus .8).
Or use a 100 foot tape measure, or 300 foot. What ever.
Or locate a sanctioned race near your house and look up the certification map at USATF.
Every measured mile will be shown on a map and described in the directions.
Pick the most convenient mile landmarks and run that mile segment.