A postmile marker typically found along California's highways. This marker is along Highway 1 in Monterey County.

California uses a postmile system on all of its state roads, including US routes and Interstate highways. The postmile markers indicate the distance a route travels through individual counties, unlike mile markers that indicate the distance traveled through a state.

Official Definitions

The following definitions are from the CALTRANS District 5 Website: ^[1]

A postmile marker is a metal paddle placed along the state highway. Each marker is stenciled with the route, county, and postmile at that location.

Listed in miles, postmile values usually increase from south to north or west to east depending upon the general direction the route follows within the state. The postmile values increase from the beginning of a route within a county to the next county line. The postmile values start over again at each county line.

Enforcement officers, maintenance forces and others use the postmile markers in the field to locate specific incidents or features with reference to the postmile system.

On some stretches of road, the following prefixes may precede the mileage on a postmile marker:

• R - Realignment
• M - Realignment of a Prior Realignment
• N - Realignment of M Mileage
• C - Commercial Lanes Paralleling Main Highway
• D - Duplication (due to meandering County Line)
• G - Reposting Duplicate PM at End of Route
• H - Realignment of Duplication
• T - Temporary Connection
• S - Spur
• L - Overlap Due to Correction or Change

See also

• Reference marker (New York)

References

1. ^ "What is a Postmile?" CALTRANS District 5 Website