All new curbs and all existing curbs which are part of any reconstruction which is contiguous to any highway shall comply with this section. In order to enable persons using wheelchairs to travel freely and without assistance, at each crosswalk, a ramp with nonslip surface shall be built into the curb so that the sidewalk and street blend to a common level. Such ramp shall not have a slope greater than one inch (1") rise per twelve inch (12") length. Where, because of surrounding buildings or other restrictions, it is impossible to conform the slope to this requirement, the ramp shall contain a slope with as shallow a rise as possible under the circumstances. In all ramps, there shall be a gradual rounding at the bottom of the slope.
(1987 Code § 21-22)