State Route 39 (California)

State Route 39 (California)
State	CA
Route	39
Type	SR
Length mi	55.52
Direction a	South
Terminus a	Pacific Coast Highway in Long Beach
Direction b	North
Terminus b	near Azusa
Counties	Los Angeles County

State Route 39 (California) is a north–south state highway in California linking the Pacific Ocean shoreline at Long Beach with the San Gabriel Mountains and access roads into the Angeles National Forest. The route connects urban centers such as Long Beach and Whittier with mountain communities near Azusa and provides recreational access to landmarks including Crystal Lake and Mount Baldy. It forms part of the regional circulation network serving commuters, freight, and tourism between the Los Angeles metropolitan area and inland recreation areas.

Route description

Coming from the south, the highway begins at the junction with the Pacific Coast Highway and traverses industrial and residential districts of Long Beach, passing near the Port of Long Beach and interchanges with Interstate 710 and State Route 1. Northward, the route proceeds through the urban corridors of Signal Hill, Pico Rivera, and Whittier, intersecting major arterials such as Interstate 5 and Interstate 605. Beyond La Habra the corridor transitions into suburban and foothill terrain approaching Brea and Fullerton, where it links with Route 90 and Route 91. Entering the foothills, the highway climbs into the San Gabriel Mountains with winding grades and narrow geometry, providing access to trailheads for Mount Baldy, Angeles Crest Highway, and the San Gabriel River watershed. The northernmost portion ascends to near Crystal Lake and terminates at a gated area within the Angeles National Forest near Azusa.

History

The corridor traces older local roads and alignments established during the late 19th and early 20th centuries that connected Los Angeles Basin communities to the San Gabriel Mountains. During the 1920s and 1930s expansion of the California state highway system, the route was formalized to serve burgeoning suburban development in Los Angeles County and the growing Port of Long Beach. Mid‑20th century improvements paralleled postwar population growth tied to industries in Long Beach and defense facilities around Seal Beach. Significant upgrades occurred during the 1950s–1970s with interchange construction near Interstate 5 and Interstate 605, reflecting planning by agencies such as the California Department of Transportation and regional bodies like the Southern California Association of Governments. In the late 20th century, natural disasters including debris flows and floods linked to storms affecting Los Angeles County prompted repeated repairs. Landslides and storm damage in the 2000s and 2010s forced long-term closures in the mountain segment, prompting debates involving stakeholders such as the United States Forest Service, local municipalities like Azusa and La Habra Heights, and advocacy groups focused on recreation management and environmental protection.

Major intersections

Major junctions include the southern terminus at Pacific Coast Highway in Long Beach, interchanges with Interstate 710, Interstate 605, and Interstate 5, connections with Route 1, Route 90 near Fullerton, and proximity to Route 91 and Route 57 in the northern Los Angeles Basin. In the foothills, intersections and junctions provide links to local roads serving Brea, Whittier Narrows, and trailheads accessing Mount Baldy Wilderness and other San Gabriel Mountains National Monument areas. The mountain terminus interfaces with gated forest roads managed by the United States Forest Service and local emergency access routes used by the Los Angeles County Fire Department.

Traffic and safety

The highway experiences varied traffic patterns: heavy urban congestion in Long Beach and the Los Angeles metropolitan area during peak commuter hours, elevated freight movements near the Port of Long Beach, and seasonal recreational surges on weekends and holidays tied to access to Mount Baldy and the Angeles National Forest. Safety concerns include collision hotspots at busy interchanges with I‑605 and I‑5, steep grades and sharp curves in the mountain section, and hazards from falling rocks, debris flows, and winter conditions affecting San Gabriel Mountains passes. Enforcement and incident response involve agencies such as the California Highway Patrol, Los Angeles County Fire Department, and municipal police departments in Long Beach and adjacent cities. Traffic management strategies have included ramp metering near freeway junctions, dynamic message signs near recreation corridors, and localized engineering countermeasures informed by studies from California Department of Transportation and regional planning commissions.

Maintenance and closures

Maintenance responsibilities rest primarily with the California Department of Transportation for the state‑maintained segments, with cooperative arrangements involving the United States Forest Service for the mountain approaches and local public works departments for urban arterials. Recurrent closures have affected the northern mountain segment due to storms, landslides, and wildfire impacts linked to events such as regional windstorms and debris flows that have hit Los Angeles County. Emergency repairs, slope stabilization projects, and roadbed reconstruction have been funded intermittently through state emergency response funds and regional grant programs overseen by entities including the Federal Emergency Management Agency. Access restrictions, gate closures, and seasonal limits are periodically imposed to protect public safety and watershed resources managed by agencies like the San Gabriel Mountains National Monument administration.

Future developments

Planned and proposed projects range from urban congestion mitigation and interchange modernization near I‑710 and I‑605 to long‑term assessments of reopening, realigning, or permanently retiring portions of the mountain route. Stakeholder discussions involve the California Department of Transportation, United States Forest Service, local governments of Azusa, Whittier, and La Habra Heights, and regional bodies such as the Southern California Association of Governments. Potential investments cited include slope stabilization, bridge rehabilitation, multimodal enhancements to integrate with commuter and transit networks like Metrolink, and environmental reviews guided by state statutes and federal regulations administered by the California Environmental Protection Agency and the United States Forest Service. Debates over cost, environmental impact, and public access will shape the corridor's future role connecting the Los Angeles Basin to the San Gabriel Mountains.

Category:State highways in California