{{short description|Highway in California}} {{Use American English|date=March 2025}} {{Use mdy dates|date=January 2025}} {{Infobox road |state=CA |type=SR |route=242 |map={{Maplink-road|raw={{Wikipedia:Map data/Wikipedia KML/California State Route 242}}}} |map_custom=yes |map_notes=SR 242 highlighted in red |section=542 |maint=[[California Department of Transportation|Caltrans]] |length_mi=3.398 |length_round=3 |length_ref=<ref name=trucklist/> |established=1987 |direction_a=South |terminus_a={{jct|state=CA|I|680}} at the [[Pleasant Hill, California|Pleasant Hill]]–[[Concord, California|Concord]] border |direction_b=North |terminus_b={{jct|state=CA|SR|4}} in Concord |counties=[[Contra Costa County, California|Contra Costa]] |previous_type=SR |previous_route=241 |next_type=SR |next_route=243 }} '''State Route 242''' ('''SR 242''') is an approximately {{convert|adj=on|3.4|mi|km}} [[state highway]] in [[Contra Costa County, California]] that links [[Interstate 680 (California)|Interstate 680]] at the [[Pleasant Hill, California|Pleasant Hill]]–[[Concord, California|Concord]] border to [[California State Route 4|State Route 4]] in Concord. Along with [[Interstate 580 (California)|Interstate 580]], [[California State Route 24|State Route 24]], Interstate 680 and State Route 4, it serves as the most direct route between the [[San Francisco Bay Area]] and the [[Sacramento–San Joaquin River Delta]] region.
In 2000, State Route 242 was widened to six through-traffic lanes for the entire route. Ramp metering is present at all onramps, and is used southbound in the morning and northbound in the evening. It was signed as part of State Route 24 until ca. 1987.
==Route description== The route begins as a freeway at [[Interstate 680 (California)|Interstate 680]] at the [[Pleasant Hill, California|Pleasant Hill]]–[[Concord, California|Concord]] border. It then heads north into Concord, meeting Clayton Road, Concord Avenue, Grant Street, and Olivera Road before meeting its north end at [[California State Route 4|State Route 4]] just west of the former [[Concord Naval Weapons Station]].<ref name="tgba">{{Cite map| publisher=Thomas Brothers| title=Bay Area Metro Street Atlas| year=2008}}</ref>
SR 242 is part of the [[California Freeway and Expressway System]],<ref name="cafes">{{CAFESystem}}</ref> and is part of the [[National Highway System (United States)|National Highway System]],<ref name=fhwa-nhs>{{FHWA NHS map|region=sanfrancisco|accessdate=September 4, 2017}}</ref> a network of highways that are considered essential to the country's economy, defense, and mobility by the [[Federal Highway Administration]].<ref name=NHS-FHWA>{{FHWA NHS}}</ref> {{Clear}}
==Exit list== {{CAinttop|exit|county=Contra Costa |length_ref=<br /><ref name=calnexus/><ref name=trucklist>{{Caltrans trucklist}}</ref><ref name=bridgelog>{{Caltrans bridgelog|date=July 2007}}</ref><ref>[[California Department of Transportation]], [http://traffic-counts.dot.ca.gov/ All Traffic Volumes on CSHS], 2005 and 2006</ref> |exit_ref=<br /><ref name=calnexus>{{cite web |date=October 30, 2018 |publisher=[[California Department of Transportation]] |work= [[California Numbered Exit Uniform System]] |url=https://dot.ca.gov/-/media/dot-media/programs/safety-programs/documents/exit/f0017871-242-a11y.pdf |title=State Route 242 Freeway Interchanges |accessdate=July 11, 2021}}</ref> }} {{CAint|exit |type=incomplete |location=Pleasant Hill |location2=Concord |mile=0.00 |mspan=2 |exit=1A |road={{Jct|state=CA|I|680|dir1=south|city1=Oakland|city2=San Jose}} |notes=No access to I-680 north; south end of SR 242; I-680 north exit 50 }} {{CAint|exit |type=incomplete |location=Concord |lspan=6 |mile=none |exit=1B |road=Gregory Lane, Monument Boulevard |notes=Southbound exit and northbound entrance }} {{CAint|exit |type=incomplete |mile=0.87 |exit=1 |road=Clayton Road – [[Concord, California|Concord]] |notes=Northbound exit and southbound entrance }} {{CAint|exit |type=incomplete |mile=1.47 |exit=1C |road=Concord Avenue |notes=No northbound exit }} {{CAint|exit |mile=2.15 |exit=2 |road={{Jct|state=CA|extra=hospital|road|Grant Street, Solano Way}} |notes=Serves [[John Muir Health]] – [[List of hospitals in California#Contra Costa County|Concord Medical Center]] }} {{CAint|exit |type=incomplete |mile=2.79 |exit=3A |road=Olivera Road |notes=Northbound exit and southbound entrance }} {{CAint|exit |mile=3.40 |exit={{nowrap|3B–C}} |road={{Jct|state=CA|SR|4|city1=Richmond|city2=Stockton|city3=Pittsburg}}<br/>Port Chicago Highway |notes=Northern end of SR 242; SR 4 exit 15A; signed as exits 3B (west, Richmond, Port Chicago Highway) and 3C (east, Stockton, Pittsburg) }} {{Jctbtm|keys=incomplete}}
==See also== *{{portal-inline|California Roads}} *{{portal-inline|San Francisco Bay Area}}
==References== {{Reflist|30em}}
==External links== {{Attached KML|display=inline,title}} {{commons category}} {{CASR external links|SR|242}} *[http://www.cahighways.org/241-248.html#242 California Highways: Route 242] *[http://www.aaroads.com/california/ca-242.html California @ AARoads.com - State Route 242]
[[Category:San Francisco Bay Area freeways|242]] [[Category:State highways in California|242]] [[Category:Roads in Contra Costa County, California|State Route 242]] [[Category:Concord, California]]