A milepost, or “mile marker,” is a 10-inch-by-36-inch green sign identifying the distance from the beginning of the interstate in each state. Milepost numbering resets to zero at the state line so that the traveling public can estimate distances before entering another state.

Mile Marker illustration

Illustration: Mile Marker along the roadway.


Mile Marker photo

Photograph: Actual Mile Marker along an interstate roadway.