The first city ordinances banning all motorized vehicles from the island were passed on July 6, 1898, with similar state park rules coming in 1901. The residents complained after a doctor's car scared their horses and caused carriage accidents, and these complaints prompted the ban. As such, other than a handful of emergency and utility vehicles as well as others by special, limited-time permit, no cars or trucks are allowed on the island and no motorized vehicles appear on M-185. During the winter months, the Mackinac Island Police sometimes patrols the island by snowmobile. Traffic on this highway is by foot, on horse, by horse-drawn vehicle, or by bicycle; M-185 is the only such state highway in the country "that allows no automobiles". As a result, the roadside litter is picked up using a horse-drawn wagon.