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.

Milepost illustration

Illustration: Milepost along the roadway.

 

Milepost photo

Photograph: Actual milepost along an interstate roadway.