This is a floating closed javascript menu.

County Route Shield

San Joaquin/Alameda/Contra Costa
County Sign Route J4

[Click here for a key to the symbols used. Some county routes were constructed with federal funds. These routes are indicated as FAP (Federal Aid Primary), FAU (Federal Aid Urban), or FAS (Federal Aid Secondary). If no funding source is shown, no federal funds were used. Note that while some segments seem to have the same attributes, they may differ in the county-local road number assigned to the segment, or in the Caltrans Map Sheet number.]

Routing Routing

  1. Cty Rte J4Durham Ferry Road from Airport Way (County Sign Route J3) to Kasson Road (FAS, 0.20 mi) [San Joaquin County]

  2. Kasson Road from Durham Ferry Road to Eleventh Street (7.25 mi) [San Joaquin County]

  3. Grant Line Road from Eleventh Street to the Tracy city limits (FAS, 3.09 mi) [San Joaquin County]

    National Trails National Trails

    Lincoln Highway Sign This segment, from Eleventh Street to G Street in Banta was part of the Lincoln Trail.

  4. Grant Line Road in Tracy (FAU, 1.75 mi) [San Joaquin County]

  5. Grant Line Road from the Tracy city limits to Byron Highway (FAS, 2.47 mi) [San Joaquin County]

  6. US Highway Shield Byron Road Highway from Grant Line Road to the Alameda county line (FAS, 5.00 mi) [San Joaquin County]

    Note: This segment was once part of US 48, later US 50.

  7. Byron Bethany Road from the San Joaquin county line to the Contra Costa county line (FAS, 1.41 mi) [Alameda County]

  8. Byron Highway from the Alameda county line to Route 4 (FAS, 6.82 mi) [Contra Costa County]

    Status Status

    According to reports, this segment may have been decommissioned, as the signs have been removed (02/2000). However, as of 2005, the Contra Costa County installed brand new signs along Byron Highway, marking it as J4. See the page on Route 239 for some proposed improvements on this route, as portiongs of County Sign Route J4 parallel unconstructed Route 239.

History and Signage Information History and Signage Information

This route was defined in 1960.

National Trails National Trails

De Anza Auto Route This route is part of the De Anza National Historic Trail.

Other WWW Links Other WWW Links

Status Status

Total mileage: 27.99 mi.

Acronyms and Explanations:

Back Arrow CR J3 Forward Arrow CR J5

© 1996-2020 Daniel P. Faigin.
Maintained by: Daniel P. Faigin <>.