§ 125. Motor vehicles. Every vehicle operated or driven upon a public highway which is propelled by any power other than muscular power, except (a) electrically-driven mobility assistance devices operated or driven by a person with a disability, (a-1) electric personal assistive mobility devices operated outside a city with a population of one million or more, (b) vehicles which run only upon rails or tracks, (c) snowmobiles as defined in article forty-seven of this chapter, (d) all terrain vehicles as defined in article forty-eight-B of this chapter, (e) bicycles with electric assist as defined in section one hundred two-c of this article, and (f) electric scooters as defined in section one hundred fourteen-e of this article. For the purposes of title four of this chapter, the term motor vehicle shall exclude fire and police vehicles other than ambulances. For the purposes of titles four and five of this chapter the term motor vehicles shall exclude farm type tractors and all terrain type vehicles used exclusively for agricultural purposes, or for snow plowing, other than for hire, farm equipment, including self-propelled machines used exclusively in growing, harvesting or handling farm produce, and self-propelled caterpillar or crawler-type equipment while being operated on the contract site.