“Sidewalk.” “Sidewalk” means the area determined as follows

(1) On the side of a highway which has a shoulder, a sidewalk is that portion of the highway between the outside lateral line of the shoulder and the adjacent property line capable of being used by a pedestrian.

(2) On the side of a highway which has no shoulder, a sidewalk is that portion of the highway between the lateral line of the roadway and the adjacent property line capable of being used by a pedestrian. [1983 c.338 §89]