Grade-separated crossings provide cyclists and pedestrians spatial separation from motor vehicles. Grade separation is generally implemented at busy intersections or across major roads. These crossings generally take the form of an overpass (bridge) or underpass (tunnel). 

Existing structures such as culverts can be retrofitted to provide a grade separated crossing.  When well designed and aligned with desire lines, grade separation reduces the road safety risk of crossing a road, and can improve the level of service by reducing delay to all users when compared with at-grade crossing provisions.  Review the planning considerations of a grade-separated facility to ensure it is suitable for the target users.