Teaching Valhalla That Hiking Is Not Flat
A walking route across a city and a hiking route up a mountain should not share the same clock.
Routing engines are good at distance, turn costs, access rules, and road classes. Hiking time is harder. A two-kilometer trail can be easy, slow, dangerous, or all three, depending on slope, descent, surface, visibility, and how the local trail network publishes reference times.
Globus routing is built on Valhalla, and Valhalla tiles already contain the graph, the route shape, and elevation. We wanted to know whether that information was enough to make hiking ETAs less optimistic, without breaking tile compatibility and without a formula that only works in one mountain range.
We built a corpus of reference hiking times, tested several formulas, rejected most of them, used a deliberately expensive research hook to find what worked, and then moved the result into production Valhalla code.