Oregon Revised Statutes Public Health and Safety § 447.310

(1) The standard for construction of curbs on each side of any city street, county road or state highway, or any connecting street, road or highway for which curbs and sidewalks have been prescribed by the governing body of the city or county or Department of Transportation having jurisdiction thereover, shall require not less than two curb cuts or ramps per lineal block to be located on or near the crosswalks at intersections. Each curb cut or ramp shall be at least 48 inches wide, where possible, and a minimum of 36 inches wide where a 48-inch width will not fit, at a slope not to exceed one-inch rise per 12-inch run. If a slope of 1:12 will not fit, a slope between 1:10 and 1:12 is allowed for a maximum rise of six inches and a slope between 1:8 and 1:10 is allowed for a maximum rise of three inches. In no case shall the slope exceed 1:8.

(2) Standards set for curb cuts and ramps under subsection (1) of this section shall apply whenever a curb or sidewalk is constructed or replaced at any point in a block which gives reasonable access to a crosswalk.