Interstate 40 goes through the Mojave Desert on its entire journey through California. I-40 starts out at a junction with Interstate 15 in Barstow. The freeway passes through Marine Corps Logistics Base Barstow before leaving the city limits. I-40 provides access to the town of Daggett but passes south of the town. After passing south of the Barstow-Daggett Airport, I-40 goes through Newberry Springs and Ludlow before traveling along the south end of Mojave National Preserve. Several miles east of the preserve, I-40 intersects US 95 and the two highways run concurrently into the city of Needles. In Needles, US 95 continues south while I-40 continues east through Mojave National Preserve and across the Colorado River into Arizona. The maximum speed limit for the entire California segment of Interstate 40 is. I-40 is part of the California Freeway and Expressway System, and is part of the National Highway System, a network of highways that are considered essential to the country's economy, defense, and mobility by the Federal Highway Administration. I-40 is eligible for the State Scenic Highway System, but it is not officially designated as a scenic highway by the California Department of Transportation. Interstate 40 from Interstate 15 to the Arizona State Line is known as the Needles Freeway, as named by Senate Concurrent Resolution 1 in 1968.
History
In 1957, the California Department of Highways proposed that the route be numbered as I-30 because of the already existing U.S. Route 40 in the state. However, this was rejected, and eventually US 40 was decommissioned in favor of I-80. Today, the Needles Freeway replaced the former Route 66 across the Mojave Desert. As a result, a number of communities along the former route like Amboy have become ghost towns. In the early 1960s, a proposal as part of Project Plowshare would have detonated 22 nuclear explosions to excavate a massive roadcut through the Bristol Mountains to accommodate a better alignment of Interstate 40 and a new rail line. This proposal was definitively abandoned in 1968. A sign in California showing the distance to Wilmington, North Carolina has been stolen several times.
Future
The State of California submitted the segment of what is now State Route 58 between Barstow and Bakersfield for chargeable Interstate approval twice, in 1956 and 1968, presumably as an extension of I-40, but it was rejected both times. As a result of these rejections, this segment of SR 58 is being upgraded to freeway standards piece-by-piece as Caltrans has funds available. Between Bakersfield and Barstow, SR 58 exists mostly as a four- to six-lane freeway with a few exceptions: a section from Mojave to California City is four lanes with at-grade intersections, and a four-lane section with at-grade crossings between the Kramer Junction and Hinkley bypasses. Caltrans completed an Interstate-grade bypass around Hinkley and a similar bypass around Kramer Junction. The bypass was opened to traffic on October 24, 2019. An extension of I-40 in California from its present western terminus in Barstow to Bakersfield, and possibly as far west as Paso Robles, has been proposed. The proposed I-40 extension would generally follow SR 58 to Bakersfield and then follow SR 46 to Paso Robles, although there is no current push to apply for Interstate designation. However, SR 46 is slowly being upgraded to Interstate standards, minus overpasses, from US 101 in Paso Robles to I-5 in Lost Hills. This would lead I-40 across two major mountain ranges, the Tehachapi Mountains and Sierra Nevada, and possibly the Diablo Range as well.
Interstate 40 Business is a business loop in Needles. It provides access to downtown Needles as Broadway Street. It also follows the former routing of US 66.
