alt Hacker NewsThey must be doing something that integrates user-contributed data because one quirk of their course planner[1] is an out-and-back plan along the same course will have non-coincident elevation profiles, even along trails where it can't be explained by switching sides of the road.
1: And their planner, in general, is garbage. I usually take the output file and run it through an AI system to fix it so it doesn't try to cue me to pointlessly switch to the other side of a major road and ride on the sidewalk.
If they’re sourcing some of their information from GPS data, the vertical precision for elevation is pretty poor, even if you’re using professional equipment. I’ve been being off a foot or tube is perfectly normal. You really need to use survey monumentation as controls. Also many states known invest in a statewide light R elevation program. It’s really too bad because they are so useful for planning and design.