alt Hacker NewsVery Cool. Thanks for making it!
I've checked out a few bike mapping apps recently and one feature I found absolutely invaluable was grade indications like http://hillmapper.com (which unfortunately seems unmaintained.)
Google Maps elevation diagrams comparing the various selected routes are nice but they do not do a good job of highlighting extreme grades. I feel like you actually want to graph the change in elevation rather than the elevation itself.
Using a route I cycled the other day (near Mission Bernal Safeway to near Diamond Heights Safeway). I think the routing may overweight bike lanes too much. For instance it will go four blocks by shared street and bike lane to avoid the two blocks on Clipper between Sanchez and Castro which are not a bike lane.
On my heavy cargo e-bike I've found there is quite a non-linear difference as the grade increases. 12% and I'll work a bit but be fine. 22% (the route Google Maps sent me...) and I'll all but collapse after a block.
Hillmapper falling apart was one of the main reasons we prioritized getting good elevation data into our router. We include steepness indicators for steep blocks and an elevation overview of the full trip and have found that combo to serve us well.
Getting between those two Safeways is rough. Bikehopper fails, it suggests the harry street steps; a non-starter for most. I’ll try to fix it. I definitely agree that grade is non-linear. We use accelerating weighting for grade so a hill that is twice as steep is more than twice as “discouraged” by the routing engine.
For bike routing I think e-bikes need a separate profile from acoustic bikes. Hill matter less and stairs are totally out of the question (this is important for routing in and out of transit centers).