The highway system of California is a network of roads owned and maintained by the state of California through the California Department of Transportation (Caltrans). Most of these are numbered in a statewide system, and are known as State Route X (abbreviated SR X). United States Numbered Highways are labeled US X, and Interstate Highways are Interstate X, though Caltrans typically uses State Route X for all classes.
Interstate Highways and U.S. Highways are assigned at the national level. Interstate Highways are numbered in a grid—even-numbered routes are east–west routes (with the lowest numbers along Mexico and the Gulf of Mexico), and odd-numbered routes are north–south routes (with the lowest numbers along the Pacific Ocean). U.S. Highways are also numbered in a grid—even numbered for east–west routes (with the lowest numbers along Canada) and odd numbered for north–south routes (with the lowest numbers along the Atlantic Ocean). There are 21 Interstate Highways in California, ranging from Interstate 5 to Interstate 980. There are seven current U.S. Highways including U.S. Route 6 and U.S. Route 395.
California State Routes are managed by Caltrans and designated by the California State Legislature. The state route's signs are in the shape of a miner's spade to honor the California Gold Rush. Each state highway in the U.S. state of California is assigned a Route (officially State Highway Route) number in the Streets and Highways Code (Sections 300-635). Since July 1 of 1964, the majority of legislative route numbers, those defined in the Streets and Highways Code, match the sign route numbers. On the other hand, some short routes are instead signed as parts of other routes — for instance, State Route 112 and State Route 260 are signed as part of the longer State Route 61, and State Route 51 is part of Interstate 80 Business. California County Routes are marked with the usual County route shield, and are assigned a letter for where they are located. For instance, county highways assigned "S" are located in Southern California, ones assigned "J" are found in Central California, and those assigned "A" are located in Northern California.
State Route 56 (SR 56) is an east–west state highway in the U.S. state of California. It runs 9.210 miles (14.822 km) from Interstate 5 (I-5) in the Carmel Valley neighborhood of San Diego to I-15. The eastern terminus of the highway is also the western end of the Ted Williams Parkway. SR 56 serves as an important connector between I-5 and I-15, being the only east–west freeway between SR 78 in north San Diego County, several miles away, and SR 52 near Marine Corps Air Station Miramar. It is also named the Ted Williams Freeway, after the San Diego-born baseball player. SR 56 was added to the state highway system in 1959 as Legislative Route 278, and was renumbered SR 56 in the 1964 state highway renumbering. Plans in 1964 were to connect SR 56 to the north end of SR 125 and continue east to SR 67, but these plans did not come to fruition. The eastern end from Black Mountain Road to I-15 was completed in 1993; the western end from I-5 to Carmel Creek Road was completed in 1995 after several lawsuits filed by the Sierra Club and other community groups. The two ends were not connected until the middle portion of the freeway was completed in 2004. The delay was largely due to funding issues and environmental concerns.
The four-lane Foresthill Bridge
was built in 1971 to replace the low crossing of the American River
on State Route 49
in preparation for the construction of the Auburn Dam
. The dam was canceled for environmental reasons, but the bridge, the tallest in California, remains along the local Foresthill Road.