The basic unit of accessibility in a pedestrian circulation network. Even on steep sites, pedestrians using motorized wheelchairs or being assisted in traveling can use curb ramps, and a connection to the street crossing should be available if there is a pedestrian walkway. Curb ramps are the only item of right-of-way construction specifically required in the DOJ title II regulation. Where new sidewalks or streets are constructed or existing pedestrian or vehicular ways are altered, curb ramps must be provided at intersections with curbs or other barriers to use. Under program accessibility in existing facilities, title II entities are required to install curb ramps along existing pedestrian routes not otherwise being altered to provide the benefits of public sidewalks to people who have mobility impairments.