The Detroit metropolitan area in southeast Michigan is served by a comprehensive network of roads and highways.

Intersecting this grid are five diagonal spokes, major arterial roads which travel from downtown to the suburbs.

Following a historic fire in 1805, Judge Augustus B. Woodward devised a plan similar to Pierre Charles L'Enfant's design for Washington, D.C. Detroit's monumental avenues and traffic circles fan out in a baroque-styled radial fashion from Grand Circus Park in the heart of the city's theater district, which facilitates traffic patterns along the city's tree-lined boulevards and parks.

[3] The Woodward plan proposed a system of hexagonal street blocks, with the Grand Circus at its center.

The precise point of origin is located in Campus Martius Park, marked by a medallion[4] embedded in the stone walkway.

Further south and west, along the Lake Erie shoreline, and through Downriver, the roads tend to fall off the grids more often, for several reasons, including remnants of the French ribbon farms and natural features preventing straight road building.

This is a common misconception by residents of Detroit, Harper Woods and Grosse Pointe, as Cadieux, Moross and Vernier appear to be extensions of their mile-road neighbors, but are in fact roads in their own right.

The highest addresses used in the Detroit system are the range 79000 to 80999, for north-south roads beyond 37 Mile Road in northern Macomb County, and from 81000 to the high 81900s in the portion of the city of Memphis that bulges about 0.5 miles (0.80 km) into St. Clair County.

The Detroit system also extends as far west as Lyon Charter Township, whose supervisor's offices are located at 58000 Grand River Avenue,[9] and as far south as the southernmost border of Wayne County.

Typically, addresses of single family homes on adjacent lots on the grid system, both within Detroit and in the suburbs, are incremented by 8, 10, 12 or more rather than by 2 as is the case in most other large cities in the United States.