Final Environmental Impact Statement/Report Released for the L.A. Northwest 138 Corridor Improvement Project

July 12, 2017
The Final Environmental Impact Statement/Environmental Impact Report for the Northwest 138 Corridor Improvement Project has been completed by the Los Angeles County Metropolitan Transportation Authority and the California Department of Transportation.

The Final Environmental Impact Statement/Environmental Impact Report for the Northwest 138 Corridor Improvement Project has been completed by the Los Angeles County Metropolitan Transportation Authority and the California Department of Transportation. The goal of the project is to improve mobility and operations and enhance safety  on SR-138 between the I-5 and SR-14 in the northern part of Los Angeles County.

A no build alternative and two build alternatives – alternative 1 (freeway/expressway plus Antelope Acres Variation Option) and alternative 2 (expressway/limited access conventional highway) – were evaluated and considered to best meet the purpose and need of the project. 

An expressway/limited access conventional highway (alternative 2) was identified as the project’s preferred alternative. The main corridor alignment proposed for the preferred alternative extends generally along or near the existing SR-138 highway for approximately 36 miles from I-5 to SR-14. Portions of SR-138 not used for the proposed improvements would remain and serve as a road for local access.

The locally preferred alternative includes: 

  • Freeway (six-lane divided): I-5 interchange to Gorman Post Road
  • Expressway (six-lane divided): Gorman Post Road to 300th Street West; access limited to intersections
  • Expressway (four-lane divided): 300th Strett W to 240th Street West; access limited to intersections
  • Limited Access Conventional Highway (four-lane): 240th Street West to SR-14; limited access restrictions
  • Other improvements to the I-5/SR-138 and SR-138/SR-14 and to the structure that crosses over SR-14

The study was funded by Measure R, the 2008 voter approved half-cent sales tax for L.A. County transportation improvements. Funding for final design and construction has not been identified at this time – although the project is eligible for several local and state funding sources. The project will be built in phases or as needed, based on demand and  identification of funding. Short- and mid-term improvements will focus on operational and safety improvements, including intersection improvements, shoulder widening and curve corrections.

This section of the 138 is located in the northwest corner of Los Angeles County. The highway is the main east-west route in the Antelope Valley and connects with Lancaster, Palmdale and other High Desert communities. The corridor is used as a bypass for goods movement and commuters when emergency closures occur on the I-5 or SR-14. Among the goals of the project is to alleviate issues associated with growing traffic and the mix of heavy-load trucks and smaller vehicles. The proposed improvements were developed to help accommodate future demand, emergency access and enhanced connections to residential and business properties located along the corridor.