Michigan Department of Transportation:Official website.
Michigan State Highways:Details on all of the state trunklines and their history, plus other highway facts.
A Guide to Highways in Upper Michigan: Gives descriptions of facilities in the Upper Peninsula as well as listing personal ideas for improvements.
BT's Detroit Road Guide: Descriptions of numbered routes.
County Road Association of Michigan: Organization representing the interests of the state's county road agencies. Site includes information on each agency.
Detroit Highways: Contains route logs, historical information, and personal observations.
Great Lakes Circle Tour: Covers the signed tours around the lakes.
Jody Aho's Northern Minnesota, Northern Wisconsin, and Michigan's Upper Peninsula Road Page: Covers the American shore of Lake Superior. Includes photos.
Michiana Roads: Information and photos covering Southwestern Michigan and North-Central Indiana (Greater South Bend).
MPG Roads: Various topics on the state as well as Georgia and Pennsylvania.
Toledo's Highways and Byways: Articles and photographs from the two-state region.
US-12 Heritage Trail: Page describing the Historic Heritage Route. Includes tour detail files, history, FAQ, newsletter, and links.