Strava can estimate the surface type, gradient, and difficulty level for running, hiking, walking, and trail running routes. From the Maps tab on the Strava mobile app, tap See Details on any suggested or saved route of the qualifying sports types and scroll down to the “Terrain” section. Swipe between the maps to preview the estimated surface type, gradient, and difficulty along the route.
We incorporate crowdsourced data from OpenStreetMap to determine surface types on routes. Dashed lines indicate the section is unpaved, solid orange indicate the section is paved, and white is unspecified.
The GPS data of the route gets cross-referenced to our elevation database to determine the gradient of the route. Descents will be yellow and inclines will be red.
We calculate difficulty based on attributes such as distance, elevation, and community completion time. More information on overall difficulty and the difficulty gradient can be found here.