Four-wheelers (ATVs) are not universally illegal, but they are heavily restricted or outright banned from operating on public paved roads, highways, and state-owned pedestrian trails in many municipalities. These restrictions exist primarily because traditional ATVs lack essential safety features required for street legal compliance—such as turn signals, airbags, specialized emission controls, and differentials designed for paved asphalt—posing severe rollover and collision hazards on high-speed roadways.