A. The city traffic engineer shall establish, designate and maintain crosswalks at intersections and other places by appropriate devices, marks or lines upon the surface of the roadway as follows: Crosswalks shall be established and maintained at all intersections where the city traffic engineer determines that there is particular hazard to pedestrians crossing the roadway subject to the limitation contained in subsection B of this section.

B. Other than crosswalks at intersections, no crosswalk shall be established in any block which is less than four hundred feet in length, and such crosswalk shall be located as nearly as practicable at midblock.