California State Route 4
|Defined by S&HC § 304|
|Maintained by Caltrans|
|Length:||197 mi (317 km)|
|Existed:||1934 – present|
|West end:||I-80 in Hercules|
| SR 242 in Concord
SR 160 in Antioch
I-5 in Stockton
SR 49 in Angels Camp
|East end:||SR 89 near Markleeville|
State Route 4 (SR 4) is a state highway in the U.S. state of California, routed from Interstate 80 in the San Francisco Bay Area to State Route 89 in the Sierra Nevada. It passes through Ebbetts Pass and contains the Ebbetts Pass Scenic Byway, a National Scenic Byway.
SR 4 roughly parallels the Sacramento-San Joaquin River Delta, a popular area for boating and fishing. There are a number of accesses to marinas and other attractions.
Route description 
State Route 4 is part of the California Freeway and Expressway System and is eligible for the State Scenic Highway System. However, it is only a scenic highway as designated by Caltrans from a point east of Arnold to SR 89. SR 4 is also known as the John Muir Parkway from I-80 in Hercules to I-680 near Martinez, named for the environmentalist John Muir. The stretch through Franklin Canyon was once known as "Blood Alley."
SR 4, an east–west highway, begins in Hercules at San Pablo Avenue next to the Interstate 80 junction as part of John Muir Parkway. (The actual parkway extends a bit past the western terminus.) The road is an expressway from its starting point until it approaches Martinez, at which point it becomes a full freeway (the California Delta Highway) passing Concord, Pittsburg, and Antioch. The John Muir National Historic Site is located directly north of Route 4 on Alhambra Avenue in Martinez. Alhambra Avenue at SR 4 is also the site of the Franklin Canyon Adobe. BART tracks run in the median of the freeway from the Port Chicago Highway interchange in Concord to the Bailey Road interchange in Bay Point, where the line currently ends at the Pittsburg/Bay Point Station. Access to that station is provided by a pedestrian bridge crossing over the eastbound lanes of Highway 4. After Antioch, the freeway turns southward at its intersection with State Route 160, turning into a suburban and rural road bypassing the Bay Area's outermost eastern suburbs (Oakley and Brentwood); this section is also known as the John Marsh Heritage Highway.
Route 4 east continues to Stockton, where it briefly joins I-5 and then enters a separate freeway (known locally as the Crosstown Freeway) routing almost directly through downtown Stockton. The route then runs concurrent with State Route 99 before running eastward into the Sierra through Angels Camp, one of the richest quartz mining sections of the Mother Lode and home of "The Celebrated Jumping Frog of Calaveras County", and Calaveras Big Trees State Park. The route runs through the 8,050 ft (2,450 m). Pacific Grade Summit on its way up to the 8,730 ft (2,660 m). Ebbetts Pass (being Northern California's highest road) and ends at State Route 89 ten miles (16 km) west of Topaz Lake, on the California–Nevada border. The portion from Arnold to its terminus is designated the Ebbetts Pass Scenic Byway, which is eventually one lane.
Through the mountains, SR 4 is not suitable for large trucks, buses, or RVs, as it becomes very steep and narrow, with no center dividing line shortly after the Mount Reba Turnoff to Bear Valley Ski area, with tight switchbacks. The pass is not plowed for snow, and thus closes during the winter months often from November through as late as May. Thus, no passage between the Mount Reba Turnoff and Markleeville is possible. The western slope is plowed and rarely closes, even for a few hours, but often has chain restrictions during and immediately following storms, usually just east of Arnold. The eastern slope is not plowed.
Although segments of Route 4 were part of the state highway system since 1909, Route 4 was officially designated as such between US Route 40 (now Interstate 80) and State Route 99 in 1934. Prior to that date, the then existing segment was officially known as the "Borden Highway", and the bridge over the San Joaquin River is still referred to as the "Borden Highway Bridge" in tidal tables. Construction of Route 4 did not finish until 1935, however.
The portion of Route 4 from US Route 40 to State Route 24 was added to the highway system in 1933 as Legislative Route Number (LRN) 106. East of the concurrency with State Route 24 to State Route 49, Route 4 was designated as LRN 75 from 1931-1934. Finally, the segment from State Route 49 to State Route 89 was signed as LRN 24 from 1909 to 1934.
From 2008 to 2009, a road built by the State Route 4 Bypass Authority, named the State Route 4 Bypass, opened in three phases, bypassing Route 4 in Oakley and Brentwood to the south and west. Many of the signs and local maps designated this extension as simply "Bypass Road." A section of Marsh Creek Road was widened to serve as the connection between the bypass built by the authority and the original Route 4 towards Stockton. In 2012, Caltrans handed over authority for State Route 4 in Oakley and Brentwood to the respective cities. In return, it gained control of the bypass and the upgraded section of Marsh Creek Road, which officially became State Route 4.
Only the portion of the bypass from California SR 160 to Lone Tree Way interchange is a multi-lane freeway. The portion from Lone Tree Way to Vasco Road is single-lane each way and have signal-controlled grade crossings at Sand Creek Road, Balfour Road and Marsh Creek Road. In May 2010, this narrow stretch of the road handled 27,000 to 30,000 vehicles per day. In 2011, Caltrans awarded $25 million toward upgrading the section from Lone Tree Way to Sand Creek Road to a full freeway and constructing an interchange at Sand Creek Road.
The freeway segment of Route 4 in Stockton is part of a proposed route to upgrade Route 99 into a future Interstate highway. Under one proposal, the new interstate would go along Route 99 from the split with I-5 at Wheeler Ridge north through Fresno to Stockton, where the proposed route would then turn west via the Route 4 freeway to a terminus at I-5.
Major intersections 
This table reflects the transfer of the State Route 4 Bypass to Caltrans in 2012. 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.
|Hercules||0.00||1A||San Pablo Avenue||At-grade intersection; former US 40|
|0.00||1B||I-80 (Eastshore Freeway) – Oakland, San Francisco, Sacramento||No exit number eastbound|
|0.78||1C||Willow Avenue||Westbound exit and eastbound entrance|
|R1.70||1||Sycamore Avenue||Eastbound exit and entrance|
|East end of freeway|
|R1.70||Claeys Lane||Interchange; westbound exit and entrance|
|2.70||3||Franklin Canyon||At-grade intersection eastbound; interchange westbound|
|West end of freeway|
|T4.89||5||Cummings Skyway to I-80 east – Crockett, Port Costa, Vallejo|
|R5.17||6||McEwen Road – Port Costa||Westbound exit and eastbound entrance|
|Martinez||R8.55||9||Alhambra Avenue – Martinez|
|R9.19||10||Pine Street, Center Avenue|
|R10.33||11||Morello Avenue, Glacier Drive|
|12.41||12A||Pacheco Boulevard – Pacheco||Former SR 21|
|12.67||12||I-680 – Benicia, Sacramento, Walnut Creek, San Jose||Signed as exits 12B (south) and 12C (north)|
|Concord||R14.67||15A||SR 242 – Concord, Oakland|
|R15.42||15B||Port Chicago Highway|
|R16.83||17||Willow Pass Road|
|R18.83||19||San Marco Boulevard, Willow Pass Road – Bay Point|
|R20.10||20||Bailey Road||Signed as exits 20A (south) and 20B (north)|
|Pittsburg||23.05||23||Railroad Avenue, Harbor Street|
|24.32||24||Loveridge Road – Pittsburg|
|Antioch||26.01||26||Somersville Road, Auto Center Drive||Signed as exits 26A (Somersville Road) and 26B (Auto Center Drive)|
|26.94||27A||Contra Loma Boulevard, L Street||Eastbound exit and westbound entrance|
|27.29||27B||G Street – Central Antioch||Closed; former eastbound exit and westbound entrance|
|R27.79||28||A Street, Lone Tree Way|
|31.13||30||SR 160 north – Rio Vista, Sacramento||Eastbound exit and westbound entrance; former SR 4 east; west end of bypass|
|Brentwood||33||Lone Tree Way|
|East end of freeway|
|Sand Creek Road||At-grade intersection; proposed interchange|
|Balfour Road||At-grade intersection; proposed interchange|
|Marsh Creek Road, Vasco Road – Concord, Livermore||East end of bypass|
|Walnut Boulevard – Brentwood, Livermore|
|43.97||Byron Highway, Marsh Creek Road – Brentwood||Byron Highway was former SR 4 west|
|Byron||R44.37||CR J4 (Byron Highway) – Byron, Tracy|
|5.96||CR J2 (Tracy Boulevard) – Tracy|
|I-5 south / Dr. Martin Luther King Jr. Boulevard – Tracy, San Francisco, Los Angeles, Angels Camp||Interchange; west end of I-5 overlap; Dr. Martin Luther King Jr. Boulevard was former SR 4 east / Charter Way|
|West end of freeway on I-5|
|65B||I-5 north – Sacramento||East end of I-5 overlap; no exit number eastbound|
|R16.62||66A||El Dorado Street, Center Street – Downtown Stockton||Serves Stockton Arena and Ballpark; no exit number eastbound|
|R17.05||66B||Stanislaus Street – Downtown Stockton||Signed as exit 66 eastbound|
|R17.71||67||Wilson Way||Former US 50 / US 99|
|R18.77||68A||Filbert Street||Signed as exit 68 westbound|
|68B||SR 99 north – Sacramento||West end of SR 99 overlap; no exit number westbound|
|18.15[N 2]||253||Main Street||Westbound exit only|
|Stockton||18.02[N 2]||253||Dr. Martin Luther King Jr. Boulevard||No westbound exit; former SR 26 west / Charter Way|
|East end of freeway on SR 99|
|SR 99 south / Farmington Road – Fresno, Los Angeles, Stockton||Interchange; east end of SR 99 overlap; Farmington Road was former SR 4 west|
|24.87||CR J5 (Jack Tone Road) – Lockeford, Ripon|
|Farmington||33.10||CR J4 (Escalon-Bellota Road) – Escalon|
|4.54||CR J14 (Milton Road) – Milton, Eugene|
|Copperopolis||R8.14||CR E15 (O'Byrnes Ferry Road) / Rock Creek Road – Copperopolis|
|Angels Camp||R21.09||SR 49 (Main Street) – San Andreas, Sonora|
|Vallecito||26.22||CR E18 (Parrots Ferry Road) – Moaning Cavern|
|3.89||SR 207 (Mount Reba Road)|
|Bullion||31.68||SR 89 to US 395 – Markleeville, Monitor Pass|
- "California Highways: State Route 4". Cahighways.org. Retrieved 2011-11-29.
- "January 1, 2006 California Log of Bridges on State Highways". California Department of Transportation. Retrieved 2011-11-29. Does not reflect the transfer of the State Route 4 Bypass to Caltrans in 2012.
- "CA Codes (shc:250-257)". Leginfo.ca.gov. Retrieved 2011-11-29.
- "CA Codes (shc:260-284)". Leginfo.ca.gov. Retrieved 2011-11-29.
- California Department of Transportation, Officially Designated Scenic Highways, accessed 2009-09-14
- 2007 Named Freeways, Highways, Structures and Other Appurtenances in California. Caltrans. pp. 116–117. Retrieved 2007-03-28.
- Cabanatuan, Michael (1999-06-10). "Project to Straighten Out Part of Highway 4". San Francisco Chronicle. pp. A–17. Retrieved 2008-03-14.
- Faigin, Daniel. "State Route 4". California Highways. Retrieved 2012-11-12.
- "State Route 4 Bypass Authority". Retrieved 2011-11-12.
- Lafferty, Justin (January 26, 2012). "Brentwood, Oakley celebrate Highway 4 transfer". Brentwood Press. Retrieved February 2, 2012.
- Coetsee, Rowena (May 28, 2010). "Safety fears still dog East County roadway, but opinions differ over causes". San Jose Mercury News.
- Lafferty, Justin (September 29, 2011). "Savings lead to Bypass progress". Brentwood Press. Retrieved 2011-11-23.
- California Department of Transportation, State Truck Route List[dead link] (XLS file), accessed February 2008
- 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 4 Freeway Interchanges, Retrieved on 2009-02-05.
- California Department of Transportation, California Numbered Exit Uniform System, State Route 99 Freeway Interchanges, Retrieved on 2009-02-05.
- State Route 4 Bypass Authority: Maps, accessed December 2007
- California @ AARoads.com – State Route 4
- Caltrans: Route 4 highway conditions
- California Highways: Route 4
- Ebbetts Pass Scenic Byway
- Scenic 4 - Ebbetts Pass Scenic Byway
- Cal-NExUS: Route 4