State Route 4 Corridor Map
Final SR 4 Congestion System Management Plan (CSMP)
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A description of State Route 4
State Route 4 (SR-4) is an east/west highway extending from I-80 in Hercules across Contra Costa County (District 4), through the counties of San Joaquin, Stanislaus, and Calaveras, and terminating at its junction with State Route 89 (SR-89) in Alpine County (District 10). The corridor serves as an interregional connection between the Bay Area, the Interstate 5 (I-50 Corridor, and the Central Valley. The corridor also serves recreational travel from Bay Area to the Delta and the Sierra Nevada Mountain Range (Sierras). The corridor elevation ranges from below sea level to 9700 feet above sea level at Ebbetts Pass. SR-4 has concurrent routing with State Route 99 (SR-99) in Stockton between the Crosstown Freeway and Farmington Road, and with State Route 49 through the City of Angels.
In District 10, SR-4 extends 141.5 miles from the Contra Costa County / San Joaquin County line transversing the San Joaquin Delta and Valley areas eastwardly across the Sierras to its eastern terminus with SR-89 in Alpine County. The SR-4 corridor provides for interregional travel by providing access between the industrial and residential areas of eastern Contra Costa County and the San Joaquin Valley. The corridor acts as a main street to many small communities in the Sierras and is vital to their economic development. SR-4 serves many recreational destinations in the Delta, Gold Country, as well as the Sierras including Calaveras Big Trees State Park and Bear Valley Ski Resort.
Corridor Specific Issues
Through San Joaquin Valley counties including the Delta:
- SR-4/Crosstown experiences recurrent peak hour congestion at junctions of Interstate 5 and State Route 99
- Not a through corridor because of two route breaks, one at I-5 and one at SR-99
- Irregular horizontal alignments along the Delta Waterways
- Older bridges over waterways
- Queuing of traffic during bridge closures
- Minimal shoulder widths
Through Mountain counties:
- Limited parallel roadway capacity
- Lack of right-of-way (“Main Street” highway) and environmental and financial constraints through communities for capacity increasing improvementsb
- Difficult Context Sensitive Solutions for roadway improvements
- Limited seasonal access due to chain control, snow gate closures, snow removal equipment, and closures due to special events, traffic incidents, and natural causes (i.e. rock slides, fallen trees, etc.)
- Heavy resort/recreational traffic all year long
- Recurrent highway and roadway traffic congestion at particular locations
- Roadways have many irregular horizontal and vertical alignments
- Minimal shoulders widths in many areas which may restrict safe bicycle and pedestrian/equestrian traffic
- Gaps and barriers within bicycle, pedestrian/equestrian facilities, and crossings
- Limited off-road parking in recreational areas
- Limited formal Park-and-Ride Facilities and Rest Areas
Corridor Mobility Improvement Account (CMIA) Projects
The CSMP requirement is noted in the Baseline Agreements of all projects receiving CMIA funding. CMIA funds have been allocated for the following improvement project in the SR 4 Corridor:
- Angels Camp Bypass
