California
California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...
are controlled and maintained by the respective counties in which they are located. However, they are generally patrolled by the state's
California Highway Patrol
The California Highway Patrol (CHP) is a state law enforcement agency of the U.S. state of California. The CHP has primary patrol jurisdiction over all California highways and roads and streets outside city limits, and can exercise law enfor ...
. They are typically major thoroughfares in rural areas, although many run through urban areas as well. Most are two-lane highways, and can accommodate high speeds and large volumes of traffic.
County route
A county highway (also county road or county route; usually abbreviated CH or CR) is a road in the United States and in the Canadian province of Ontario that is designated and/or maintained by the county highway department. Route numbering can ...
s are typically designated with a letter (A, B, D, E, G, J, N, R, or S, depending on the region of the state, with several counties split between two region prefixes) followed by a number (example: G2). Therefore, the county routes are sorted alphabetically, from the northernmost region of California to the southernmost region. Routes with letters (A, B, D) are in the region of
Northern California
Northern California (colloquially known as NorCal) is a geographic and cultural region that generally comprises the northern portion of the U.S. state of California. Spanning the state's northernmost 48 counties, its main population centers incl ...
, letters (E, G, J) are in
Central California
Central California is generally thought of as the middle third of the state, north of Southern California, which includes Los Angeles, and south of Northern California, which includes San Francisco. It includes the northern portion of the San J ...
, and (N, R, S) are in
Southern California
Southern California (commonly shortened to SoCal) is a geographic and Cultural area, cultural region that generally comprises the southern portion of the U.S. state of California. It includes the Los Angeles metropolitan area, the second most po ...
. Routes in
Lake
A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much large ...
and
San Bernardino
San Bernardino (; Spanish language, Spanish for Bernardino of Siena, "Saint Bernardino") is a city and county seat of San Bernardino County, California, United States. Located in the Inland Empire region of Southern California, the city had a ...
Counties are designated by numbers only.
The level of signage varies by county. In
San Diego County
San Diego County (), officially the County of San Diego, is a county in the southwestern corner of the U.S. state of California. As of the 2020 census, the population was 3,298,634, making it California's second-most populous county and the fi ...
, reassurance markers are placed as frequently as they would be on state highways. In other counties, some county routes are completely unsigned. For most county routes, signage may be found at the beginning and end and at major junctions; reassurance markers are rare and are placed at distant intervals. With a handful of exceptions (one example being S2), county routes are typically referred to by their street name (e.g. Angeles Forest Highway or Kanan Dume Road) rather than their route designation.
These routes are all part of the California Route Marker Program, which was established in 1958. This program was incorporated into the National Uniform County Route Marker Program created by the