Unconstructed state highways in California

Route 11 was a planned route from the northerly border of the new Federal Port of Entry and east of the Otay Mesa Port of Entry to near the junction of State Route 125 and State Route 905. Between 1964 and 1981, present Route 110 was designated as Route 11 including the full length of the Harbor and Pasadena freeways as well as the segment of Gaffey Street in San Pedro between 9th Street and Route 47 and the segment of Arroyo Parkway in Pasadena between Glenarm Street and Colorado Boulevard.

Route 48 was originally planned to run from Ridge Route Road (approximately four miles east of Interstate 5) near Quail Lake in Los Angeles County to Route 122 near the Los Angeles/San Bernardino County Line. The segment between Ridge Route Road and State Route 14 (north of Lancaster) was to replace the segment of State Route 138 between Ridge Route Road and Route 14 because State Route 138 between Ridge Route Road and Route 14 was to be rerouted via a southeastely course through or paralleling Oakdale and Pine Canyons to meet Route 14 in Palmdale opposite the easterly continuation of Route 138. The planned rerouting was known as the Metropolitan Bypass. In the mid 1960s, because of constructability issues on the proposed realignment of Route 138 through or near Oakdale and Pine canyons, the westerly end of Route 48 was moved east to the intersection of 170th Street West with present Route 138 where Route 138 was to leave its present alignment to head toward Palmdale. In 1995, the segment of State Route 48 between 170th Street West and Route 14 north of Lancaster was transferred to State Route 138. Route 48 was re-defined to run between Route 14 near Lancaster and to-be-constructed Route 122 near the Los Angeles/San Bernardino County Line

Route 64 is defined from State Route 1 near Malibu Beach to Interstate 5 south of San Fernando.

Route 81 is defined from Interstate 215 east of Riverside to Interstate 15 south of Devore.

Route 100 was a planned loop in Santa Cruz, running from State Route 1 on the west side of the city, through the downtown area and terminating in the vicinity of the Route 1/State Route 17 junction. Ocean Street is believed to parallel a portion of the planned alignment.

Route 122 is planned to run from State Route 14, south of Palmdale, heading northeast past Edwards Air Force Base to State Route 58.

Route 230 is set to run from U.S. Highway 101 near the south city limits of San Francisco to Route 280 in San Francisco.

In 1964, this highway ended at an unconstructed Route 87. (Route 87 in turn was to have run on the east side of Route 101, over the San Francisco Bay.) In 1970, the portion of former Route 87 from Route 230 to Route 280 was transferred to Route 230. It is speculated that this route would be the approach to a "Southern Crossing" of the bay.

Route 234 is an unconstructed southern bypass of Stockton, set to run from Route 5 to Route 99 via French Camp. French Camp Road parallels the defined alignment.

Route 235 is an unconstructed northern bypass of Stockton, set to run from Route 5 to Route 99 north of the Calaveras River. Eight Mile Road parallels the defined alignment.

Caltrans has no plans to build either bypass or adopt either traversable road as a state highway.

Route 239 is defined to begin west of Tracy at Interstate 580 and terminate near Brentwood at State Route 4. In 2005, the federal legislation known as SAFETEA-LU provided $14 million for the purpose of studying the route's corridor and funding its construction. The route is presently passable as the mostly two-lane undivided County Route J4, which carries the name Byron Highway for most of its length.

Route 249 is set to run from Route 2 north of La Cañada Flintridge to Route 14 south of Palmdale. The route would cut through the San Gabriel Mountains and the Angeles National Forest. It would connect with an also-unbuilt extension of Route 118 in or near Big Tujunga Canyon. Angeles Forest Highway, Los Angeles County Route N3, parallels the defined alignment.

In recent years, there has been talk of constructing a highway parallel to Route 249, which would tunnel through the mountains. According to the L.A. Daily News, Los Angeles County and Palmdale would spend $125,000 on a new study regarding building a highway under the Angeles National Forest by tunneling through the San Gabriel Mountains. A separate study conducted in 2002 looked at building the highway as a privately financed toll road. Said study concluded that it may cost $2.2 billion and was unlikely to pay for itself with tolls low enough to be acceptable to motorists. Previous plans have looked at creating a 21-mile-long highway that would branch off the Antelope Valley Freeway south of Palmdale and head south and a little west to the Foothill Freeway at its intersection with the Glendale Freeway.

Route 251 is an unconstructed state highway with two separated segments:

• Route 580 near Point San Quentin to Route 101 near Greenbrae.
• Route 101 near San Rafael to Route 1 near Point Reyes Station.

Sir Francis Drake Boulevard parallels the first defined segment. The second segment was added to Route 251 in 1984 as a transfer from Route 17, the latter route having been renumbered as Interstate 580 across the San Rafael-Richmond Bridge.

Originally, this was to have been the Point Reyes Freeway. Environmental concerns and costs killed this freeway.

Route 257 is a planned freeway from Route 34 in the vicinity of Oxnard to U.S. Highway 101 in Ventura. It was defined in 1965. 5th Street and Harbor Boulevard west of Route 1 parallel the defined alignment. This route was still on the Caltrans District 7 Master Plan Status Map in 2003.

Route 276 is set to run from Route 198 near Three Rivers, just south of the entrance to Sequoia National Park, to Oak Grove. It was defined in 1976. Its adopted alignment parallels the M375 road in Tulare County and approaches another park entrance. Caltrans has no plans to build Route 276 or upgrade the M375 road.

Originally, it was intended to be a toll road that would serve a Disney development at Mineral King. A portion of the route to Mineral King was later rescinded. The deleted segment is now within Sequoia National Park. It was not in the park at the time of adoption, nor at the time of recission.