“Crosswalk” is either:
(a) That portion of a roadway included within the prolongation or connection of the boundary lines of sidewalks at intersections where the intersecting roadways meet at approximately right angles, except the prolongation of such lines from an alley across a street.
(b) Any portion of a roadway distinctly indicated for pedestrian crossing by lines or other markings on the surface.
Notwithstanding the foregoing provisions of this section, there shall not be a crosswalk where local authorities have placed signs indicating no crossing.
(Enacted by Stats. 1959, Ch. 3.)