Wheelchair Terrain Classification System (WTCS) - Erik Kondo

Updated: Jan 11, 2019

The WTCS is a classification system for rating terrain. It provides wheelchair users, designers, and product manufacturers a means to easily describe and compare differ

ent types of terrain encountered by wheelchair users. It is not descriptive enough to say that something is capable of “Off-Road” navigation. Off-Road could be anything from Class III-Class VI. Therefore, the WTCS allows for more accurate and useful descriptions.

Class I – Flat, hard, and spacious surfaces with ample turning room and no obstacles. The terrain is ideal for wheelchair use. Some examples are malls, universities, hospitals, large and modern office buildings.

Class II – Relatively smooth and mostly even surfaces. The terrain is fairly easily navigated using a wheelchair. Examples are carpets, sidewalks with minor cracks and minimal uneven surfaces, wheelchair ramps, low thresholds, minor side slopes, curb cuts, brick sidewalks.

Class III – Rougher, softer, and more uneven surfaces. Terrain can be managed using a wheelchair with some effort. Examples are wide stone dust paths, packed gravel, packed dirt, moderate bevels and side hills, lawns, low curbs, accessible nature trails, well maintained dirt roads.

Class IV – Tricky for wheelchair navigation. Much rougher, much softer, and much more uneven and narrow surfaces with some obstacles. Characteristics are large cracks, roots and rocks, curbs, loose gravel, shallow sand, narrowish paths, dirt, rocky slabs, meadows, side slopes, wet and soft ground.

Class V – This terrain is very difficult to manage using a standard wheelchair. Adaptive equipment is advised. It is characterized by very rough surfaces, large cracks, drop-offs, creek beds, steep side slopes, narrow trails with obstacles, large roots, rocks, soft sand, obstructions, muddy, snowy, icy surfaces, shallow water, steps, stairs.

Class VI – This terrain is impossible for wheelchair navigation. It requires the wheelchair user to obtain major assistance to navigate even with adaptive equipment. It is characterized by large boulders, deep snow, extreme side slopes, deep water, major obstructions, unstable surfaces, steep steps, uneven and/or spiral stairways.

Terrain can be further classified in terms of incline and/or decline on a scale of 0 – 10. Where 0 represents zero incline/decline, and 10 represents a severe incline/decline.


Class IV.2 is a rough nature trail that is mostly flat.

Class II.8 is a steep paved road.

Class V.7 is a hilly single track mountain bike trail.