No person shall drive a motor vehicle on or across a sidewalk, except that a vehicle may be driven at a reasonable speed, but not more than five miles per hour, on or across a sidewalk in such manner as not to interfere with the safety and passage of pedestrians thereon, who shall have the right of way, when it is reasonable and necessary: (a) to gain access to a public highway, private way or lands or buildings adjacent to such highway or way; (b) in the conduct of work upon a highway, or upon a private way or lands or buildings adjacent to such highway or way, or (c) to plow snow or perform any other public service, for hire, or otherwise, which could not otherwise be reasonably and properly performed.
New York Legal Code