4.7 CURB RAMPS 4.7.1    Location Curb ramps complying with 4.7 shall be provided wherever an accessible route crosses a curb. 4.7.2    Slope Slopes of curb ramps shall comply with 4.8.2.   Transitions from ramps to walks, gutters, or streets shall be flush and free of abrupt changes. Maximum slopes of adjoining gutters, road surface immediately adjacent to the curb ramp, or accessible route shall not exceed 1: 20 (5%). 4.7.3    Width The minimum width of a curb ramp shall be 36 in (915 mm), exclusive of flared sides. 4.7.4    Surface Surfaces of curb ramps shall comply with 4.5. 4.7.5    Sides Of Curb Ramps If a curb ramp is located where pedestrians must walk across the ramp, or where it is not protected by handrails or guardrails, it shall have flared sides; the maximum slope of the flare shall be 1:10. Curb ramps with returned curbs may be used where pedestrians would not normally walk across the ramp. 4.7.6    Built-Up Curb Ramps Built-up curb ramps shall be located so that they do not project into vehicular traffic lanes.  Fig. 13. 4.7.7    Detectable Warnings Superseded Regulation These requirements are suspended temporarily until July 26, 1998. 4.7.8    Obstructions Curb ramps shall be located or protected to prevent their obstruction by parked vehicles. 4.7.9    Location At Marked Crossings Curb ramps at marked crossings shall be wholly contained within the markings, excluding any flared sides. Per Fig. 15. 4.7.10    Diagonal Curb Ramps If diagonal (or corner type) curb ramps have returned curbs or other well-defined edges, such edges shall be parallel to the direction of pedestrian flow. The bottom of diagonal curb ramps shall have 48 in (1220 mm) minimum clear space as shown in Fig. 15(c) and Fig. 15(d). If diagonal curb ramps are provided at marked crossings, the 48 in (1220 mm) clear space shall be within the markings (see Fig. 15(c) and Fig. 15(d)). If diagonal curb ramps have flared sides, they shall also have at least a 24 in (610 mm) long segment of straight curb located on each side of the curb ramp and within the marked crossing (see Fig. 15(c)). 4.7.11    Islands Any raised islands in crossings shall be cut through level with the street or have curb ramps at both sides and a level area at least 48 in (1220 mm) long between the curb ramps in the part of the island intersected by the crossings (see Fig. 15(a) and Fig. 15(b)).