MileCheckHow far apart are mile markers?
One mile, measured along the road. Some busy freeways add signs with a decimal every tenth of a mile. In Canada the signs are kilometre markers.
Why the gap isn't always exactly a mile
A highway gets rebuilt. A curve is straightened or a section is moved. States don't always renumber every sign after that, so one stretch can run a little long or a little short until they do.
Signs also have to fit the roadside. The federal sign manual lets a post shift a short distance from its exact mile to clear a bridge, a ramp or other obstacle, and says to leave it out if it can't fit nearby.
Counting your speed with them
At 60 mph you pass one mile marker a minute. It is a rough check on your speedometer, not a precise one.
Places they are farther apart
Some states only sign every other mile on certain roads, and signs go missing. If you can't find one, the next exit number or a town name helps.
See your mile marker as you drive
MileCheck shows your nearest mile marker, the highway and your direction. Premium adds live state DOT feeds for the road ahead and the map, with a 2-week free trial. It runs on CarPlay and Android Auto.
Questions, answered
How far apart are kilometre markers in Canada?
It depends on the province and the highway. Our Canada page goes province by province.
Are the tenth-of-a-mile signs on every highway?
No. They are mostly on urban freeways.