(1) Where sidewalks, shoulders or a combination thereof exists, a crosswalk is the portion of a roadway at an intersection, not more than 20 feet in width as measured from the prolongation of the lateral line of the roadway toward the prolongation of the adjacent property line, that is included within:
(a) The connections of the lateral lines of the sidewalks, shoulders or a combination thereof on opposite sides of the street or highway measured from the curbs or, in the absence of curbs, from the edges of the traveled roadway; or
(b) The prolongation of the lateral lines of a sidewalk, shoulder or both, to the sidewalk or shoulder on the opposite side of the street, if the prolongation would meet such sidewalk or shoulder.
(2) If there is neither sidewalk nor shoulder, a crosswalk is the portion of the roadway at an intersection, measuring not less than six feet in width, that would be included within the prolongation of the lateral lines of the sidewalk, shoulder or both on the opposite side of the street or highway if there were a sidewalk. [1983 c.338 §36]