The US Highways in Michigan are the segments of the national United States Numbered Highway System that are owned and maintained by the state of Michigan, totaling 2,300 miles (3,701 km). The longest of these is US Highway 23 (US 23) at around 362 miles (583 km). On a national level, the standards and numbering for the system are handled by the American Association of State Highway and Transportation Officials (AASHTO), while the highways in Michigan are maintained by the Michigan Department of Transportation (MDOT).