There are 45 routes assigned to the "J" zone of the California Route Marker Program, which designates county routes in California. The "J" zone includes county highways in Alameda, Calaveras, Contra Costa, Fresno, Kern, Inyo, Mariposa, Merced, Sacramento, San Benito, San Joaquin, Stanislaus, and Tulare counties.
J1
County Route J1 (CR J1) is a county highway in San Benito and Fresno counties in the U.S. state of California. It runs from State Route 25 in Paicines to State Route 33 in Mendota. The route is known as Panoche Road, Little Panoche Road, Shields Avenue, Fairfax Avenue, and Belmont Avenue.
The route begins in Paicines in San Benito County at State Route 25. Between Paicines and Panoche Valley, CR J1 is known as Panoche Road. Its north–south portion between Panoche Valley and Fresno County is called Little Panoche Road. In Fresno County, the route then intersects with Interstate 5 and terminates in Mendota at State Route 33 near State Route 180 in the Central Valley. East of Interstate 5, the alignment of CR J1 follows Fresno County's West Shields Avenue (which is exit 379 off of Interstate 5). Shields Avenue ends at North Fairfax Avenue. CR J1 continues south on Fairfax Avenue to West Belmont Avenue, where CR J1 proceeds east on Belmont Avenue until its end at SR 33 in Mendota. Belmont Avenue continues east without the county route designation to SR 180.
Panoche Road lies within the corridor of an unbuilt Route 180 segment. No current plan exists to extend Route 180 westward from Mendota past Interstate 5 and into San Benito County.
Parts of J1 just west of I-5 are gravel rather than paved.
Major intersections
J2
County Route J2 (CR J2), or I-580 Alternate, is a county highway that is made up of a series of streets and roads in Alameda and San Joaquin counties in the U.S. state of California. It runs from the Portola Avenue overpass at Interstate 580 in Livermore to State Route 4 near the community of Holt. The route is known as portions of Portola Avenue and Livermore Avenue, Tesla Road, Corral Hollow Road, and portions of Lammers Road and Tracy Boulevard.
Route description
County Route J2 begins at the Portola Avenue overcrossing of Interstate 580 in Livermore. It was a former partial interchange that closed permanently in 2011 due to the interchange that opened with Isabel Avenue (State Route 84) west of Portola. The route follows Portola to Livermore Avenue, where CR J2 turns southward to pass through Livermore's downtown. The highway continues past the southeast edge of Livermore to become Tesla Road and rise into the Diablo Range, which separates the outer San Francisco Bay Area from the San Joaquin Valley.
At the Alameda-San Joaquin county line, CR J2 becomes Corral Hollow Road and enters the narrow valley of the same name. Upon approaching the San Joaquin Valley, the road turns northward, meeting Interstate 580 again and arriving at the southern subdivisions of Tracy. After passing through this city, the road passes under Interstate 205 (with no access), shifts briefly onto Lammers Road, and soon turns northward onto Tracy Boulevard. CR J2 then crosses the sea-level Union and Roberts Islands in the San Joaquin-Sacramento River Delta before terminating at State Route 4.
Major intersections
J3
County Route J3 (CR J3) is a county highway that runs north-south through Stanislaus and San Joaquin counties in the U.S. state of California. It runs from State Route 132 east of Vernalis to State Route 12 (Kettleman Lane) in Lodi. The route is known as Kasson Road, Airport Way, West Lane, and Hutchins Street.
Route description
The route begins east of Vernalis as Kasson Road, running northward from the road's intersection with State Route 132. After almost the route meets Airport Way and follows it northward past Manteca, Lathrop, and French Camp into Stockton. CR J3 then follows West Lane out from Stockton and becomes Hutchins Street for the route's last . The route reaches its northern end at State Route 12 in Lodi.
The highway is also known as Stanislaus County Route J3 and San Joaquin County Route J3, though all but of the route is within San Joaquin County.