The key step_count gives the number of individual steps for a way tagged with highway=steps.
The key is also used with various kinds of barrier=stile (q.v.) notably stepover and ladder stiles, and sometimes squeezer stiles.
- Navigation software for blind persons can tell the number of steps, see OSM for the blind.
- Navigation and routing software for wheelchair drivers avoids steps. Profiles for persons with a walking handicap can allow single steps but avoid staircases etc., see Wheelchair routing.
- CycleStreets uses the step count, as in some cases it is better to carry a bike over a few steps, than to cycle a much bigger route.
- OSM2World uses this tag to render the correct number of steps in its 3d visualisation.
- This is currently not used by any known 2d rendering application. A very detailed rendering could include this value as a number on or near the steps.
- Step count on stiles can be an aid to estimating accessibilty for people with some limitations in mobility (e.g., older people).
steps is also used with usually the same semantics. This latter key is more popular in usage on stiles, but has also been used for other, adjectival tagging, values (yes, no, escalator). Step_count is to be preferred as it is not ambiguous.