Distances shown on COTREX are "top-down" distances and may vary from the actual distance in the following ways:
- Elevation change may cause the distance to be slightly under-reported. The amount of this error depends on the average grade:
• 0% Grade: 0 miles of error per mile
• 10% Grade: 0.005 miles of error per mile
• 20% Grade: 0.019 miles of error per mile
• 45% Grade (Manitou Incline): 0.088 miles of error per mile
- Differences between the path shown on the map and the path in real life may cause distance to be more or less than the shown amount. Very small switchbacks or zigs and zags not captured on the map may cause distances to be under-reported. This effect is likely very minimal.
- For trip recordings, noise from the GPS may cause reported distances to be greater than the actual amount. Trips in heavy tree cover where the GPS signal is weak will be affected more than trips with a clear view of the sky. COTREX does attempt to filter out some of the noise when computing the total length of your trip, but there is no fool proof method of guaranteeing that the distance will be 100% accurate. Different apps use different filtering methods, so there may be discrepancies between how apps report distance.