California State Route 138
|Defined by S&HC § 438|
|Maintained by Caltrans|
|Length:||105.376 mi (169.586 km)
SR 138 is broken into pieces, and the length does not reflect the SR 14 overlap that would be required to make the route continuous.
|West end:||I‑5 near Gorman|
| SR 14 in Palmdale
I‑15 near Cajon Pass
|East end:||SR 18 near Crestline|
State Route 138 is an east–west state highway generally following the northern foothills of the San Gabriel Mountains of southern California, USA from its junction with Interstate 5 south of Gorman eastward to Mount Anderson Junction, its eastern junction with State Route 18 south of Crestline in the San Bernardino Mountains. Except for the western two miles (3 km) of the route between Interstate 5 and just east of Gorman Post Road and a segment shared with State Route 14 between Avenue D in Lancaster and Palmdale Boulevard in Palmdale, it is all surface road, mostly undivided two-lane road. The remaining section of the Ridge Route, California's first highway connecting the San Joaquin Valley to the Los Angeles Basin, ends at 138 in Gorman.
The western leg of State Route 138 traverses the Lancaster Freeway from Interstate 5 to Gorman Post Road, Lancaster Road from Gorman Post Road to 245th Street West near Neenach School, and Avenue D from 245th Street West to Route 138s north junction with State Route 14. The Lancaster Freeway has four lanes, two for each direction of travel. Both Lancaster Road and Avenue D are 2-lane conventional roads; Avenue D is on a straight alignment over its 22 miles (35 km) between 245th Street and State Route 14.
After its co-routing with the Antelope Valley Freeway (SR 14) through Lancaster and Palmdale, it passes through Palmdales eastside as four-laned Palmdale Boulevard, 47th Street East, and Fort Tejon Road to Avenue T. At Avenue T it tapers to two lanes and continues straight ahead on Pearblossom Highway through Littlerock, Pearblossom, and Llano to its west junction with State Route 18. Route 18s western terminus siphons off Las Vegas-bound travelers from 138. At its west junction with State Route 18, State Route 138 turns southeast on Antelope Highway to the Los Angeles/San Bernardino County line where it loses its alternative name, Antelope Highway.
Between the county line and Interstate 15, State Route 138 traverses very mountainous and scenic terrain and it connects with State Route 2 that leads to winter resort areas in the San Gabriel Mountains used largely by residents of greater Los Angeles and greater San Diego. State Route 138 then descends through the West Cajon Valley and crosses Interstate 15 in the Cajon Pass. From Interstate 15 to State Route 173, near the northwest corner of Silverwood Lake, traffic on State Route 138 is rather sparse. The remaining road past Silverwood Lake is mountainous, narrow, and twisting, and not a prime mountain route to the San Bernardino Mountain resorts. The entire segment from Interstate 15 to the eastern terminus of State Route 138 at Mount Anderson Junction is known the El Cajon-Skyline Forest Highway.
Safety and Construction
Because of its twisting, mountainous segments and overloaded traffic conditions on its eastern leg, State Route 138 east of Palmdale and west of Interstate 15 is the site of numerous serious auto accidents as of 2004, according to CHP data. One of the chief contributors to accidents on Route 138 of late is drivers passing on the two-lane highway in unsafe conditions. A notable accident in 2003 involved a pickup truck driven by an unlicensed driver leaving the roadway and plunging into the California Aqueduct, killing four occupants of the vehicle and leaving the sole survivor quadriplegic. The State of California paid a $10 million settlement to the victims' family . The area surrounding the highway is also prone to brush fires and flash floods.
A project to widen the highway to four lanes and add shoulders between Ave T in Palmdale and Highway 18 in Llano was announced by the California Department of Transportation in 2009. Work was projected to be completed by Spring 2012. However, as of December 2012, work on the project was still ongoing and several portions remain two lanes.. Improvements to the six-mile stretch between Highway 18 and the Los Angeles/San Bernardino County Line, including widening the shoulders and installing rumble strips, were proposed in February 2013, with no timeline for completion being given.
Parts of the distinctive highway were used in the filming of the movie The Long, Long Trailer, a 1954 comedy with Lucille Ball and Desi Arnaz. Despite the rapid growth of Southern California in the ensuing fifty years, the segment shown in the movie is little changed since the movie was filmed.
A proposed bypass to the north of downtown Palmdale has been studied by Caltrans. The bypass would be located east of the Antelope Valley Freeway and south of LA/Palmdale Regional Airport along Avenue P-8, reconnecting with the current SR 138 east of Palmdale.
Except where prefixed with a letter, postmiles were measured on the road as it was in 1964, and do not necessarily reflect current mileage. R reflects a realignment in the route since then. The numbers reset at county lines; the start and end postmiles in each county are given in the county column.
|R0.00||I‑5 (Golden State Freeway) – Los Angeles, Sacramento||Westbound exit and eastbound entrance|
|R0.24||Quail Lake Road||Westbound exit and eastbound entrance|
|East end of freeway|
|1.71||Gorman Post Road – Gorman||Former US 99 north|
|4.11||CR N2 (Old Ridge Route Road)||Former US 99 south|
|SR 14 north (Antelope Valley Freeway) / Avenue D (to Sierra Highway) – Mojave||Interchange; west end of SR 14 overlap|
|West end of freeway on SR 14|
|R72.00[N 1]||47||Avenue F|
|Lancaster||R70.99[N 1]||46||Avenue G|
|R69.99[N 1]||45||Avenue H|
|R68.97[N 1]||44||Avenue I|
|R67.96[N 1]||43||Avenue J (CR N5)||Eastbound exit and westbound entrance|
|R67.39[N 1]||43||20th Street West||Westbound exit and eastbound entrance|
|R66.73[N 1]||42||Avenue K|
|R65.68[N 1]||41||Avenue L|
|Lancaster–Palmdale line||R64.68[N 1]||40||Avenue M||Also known as Columbia Way|
|Palmdale||R63.67[N 1]||39||Avenue N|
|R61.77[N 1]||37||10th Street West||Eastbound exit and westbound entrance; serves LA/Palmdale Regional Airport|
|R61.37[N 1]||37||Rancho Vista Boulevard (Avenue P)||Westbound exit and eastbound entrance; serves LA/Palmdale Regional Airport|
|East end of freeway on SR 14|
|SR 14 south (Antelope Valley Freeway) / CR N2 (Palmdale Boulevard) – Los Angeles||Interchange; east end of SR 14 overlap|
|44.42||Sierra Highway||Former US 6 / SR 14|
|48.59||50th Street East, Palmdale Boulevard|
|51.41||Pearblossom Highway, Avenue T – Los Angeles|
|Pearblossom||60.17||CR N6 (Longview Road) – Valyermo, Devil's Punchbowl, Big Rock Camp|
|63.68||165th Street East – Lake Los Angeles, Crystalaire, Valyermo|
|Llano||CR N4 (Largo Vista Road)|
|69.30||SR 18 east (Palmdale Road) – Victorville|
|Pinon Hills||2.91||Phelan Road, Green Road – Phelan, Hesperia|
|5.76||Sheep Creek Road – Phelan||Interchange; westbound exit only|
|6.66||SR 2 west (Angeles Crest Highway) – Wrightwood, Big Pines|
|R15.20||I‑15 (Mojave Freeway) – Victorville, San Bernardino||Interchange|
|Hesperia||R23.96||SR 173 – Hesperia|
|R28.48||Cleghorn Road – Silverwood Lake||Interchange|
|R37.85||SR 18 – Lake Arrowhead, San Bernardino||Interchange|
|1.000 mi = 1.609 km; 1.000 km = 0.621 mi
- Indicates that the postmile represents the distance along SR 14 rather than SR 138.
- January 1, 2006 California Log of Bridges on State Highways
- CA Codes (shc:250-257)
- CA Codes (shc:260-284)
- Staff. "State Truck Route List" (XLS file). California Department of Transportation. Retrieved August 21, 2012.
- California Department of Transportation, Log of Bridges on State Highways, July 2007
- California Department of Transportation, All Traffic Volumes on CSHS, 2005 and 2006
- California Department of Transportation, California Numbered Exit Uniform System, State Route 14 Freeway Interchanges, Retrieved on 2009-01-26.