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 Routes at the top of the screen. Select any of the Community Routes and scroll down to the Terrain section. Swipe between the maps to preview the estimated surface type 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 indicates 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.