State Route 178 (SR 178) is a state highway in the U.S. state of California that exists in two constructed segments. The gap in between segments is connected by various local roads and State Route 190 through Death Valley National Park. The western segment runs from State Route 99 in Bakersfield and over the Walker Pass in the Sierra Nevada to the turnoff for the Trona Pinnacles National Natural Landmark. The eastern segment runs from the southeasterly part of Death Valley to Nevada State Route 372 at the Nevada state line. SR 178 serves many different purposes. It connects Downtown Bakersfield with East Bakersfield and Lake Isabella. It is one of three crossings over the Sierra Nevada south of Yosemite (SR 120, Tioga Pass Road), connecting the southern San Joaquin Valley with the upper Mojave Desert and the Owens Valley. This also provides access to Death Valley National Park. If the unconstructed portion were built, it would also provide an easy route between Ridgecrest, California and Las Vegas, via Pahrump, Nevada. Route description SR 178 is part of the California Freeway and Expressway System, and through Bakersfield and Ridgecrest 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. It is eligible for the State Scenic Highway System, but it is not officially designated as a scenic highway by the California Department of Transportation. Western segment The first segment starts at State Route 99 just west of Downtown Bakersfield. The road continues as 24th Street but then splits at B Street, utilizing 24th Street for westbound traffic and 23rd Street for eastbound traffic through Downtown Bakersfield. SR 178 becomes a freeway as it leaves Downtown and winds through East Bakersfield. The freeway then travels east as it enters Northeast Bakersfield. A mile east of the Morning Drive interchange, the freeway segment ends with the first at-grade intersection at Canteria Drive. The highway continues through the rural, but growing Rio Bravo section of Bakersfield, crossing SR 184. Turning northeast, the road narrows to a 4-lane highway and continues to the mouth of Kern Canyon (which is also the northeastern city limits of Bakersfield). For the next approximately 8 miles, the route is a narrow 2-lane road (average width of 18 ft. to 24 ft.), as it ascends the lower Sierra Nevada. Average speed is