Congestion Relief 

State Route 120/Union Interchange

One novel project already in place to relieve traffic congestion and improve safety is the State
Route 120/Union Road diverging diamond interchange in Manteca. This pioneering design
allows traffic moving in two directions to temporarily cross to the left side of the road, moving
more traffic through the intersection without increasing lanes or traffic signals, providing
easier access to the highway, and improving safety for motorists, pedestrians and cyclists. It is
also less expensive to build than traditional highway interchanges and has a smaller footprint.
This award-winning project was the first diverging diamond interchange built in California
and received Measure K 

Union Diamond


Interstate 205 Managed Lanes

Measure K is funding an environmental analysis of a project that will be years in the making —
widening and other improvements to Interstate 205 providing easier, safer travel from the San 
Joaquin region to jobs, entertainment and recreation in the San Francisco Bay Area. Right now 
I-205 through Tracy sees heavy truck and commuter traffic and congestion. The analysis for the
I-205 Manage Lanes project will look at possibly including carpool lanes, bus and/or passenger
rail service in the median, and toll lanes, the first in the region. And depending on the ultimate
plan, overpasses, underpasses and interchanges will be altered as needed. Up to four transit
hubs could include park-and-ride lots, electric vehicle charging stations, and bus and train
stops, making it easier for commuters and others to get around. The project approval and

environmental document are scheduled to be completed in fall 2023.

I-205 Widening


State Route 99/120 Connector Project

Motorists will be able to travel in and through San Joaquin County more safely and smoothly
with Measure K funding being used to rebuild the State Route 99/120 interchange in Manteca.
The improvements to ease traffic congestion, improve traffic flow, and eliminate weaving and
merging issues that can cause terrible traffic wrecks will come in several phases. It is one of
several priority projects to greatly improve travel and safety along the SR 99 corridor. SJCOG
staff has been working to find funds to eliminate shortfalls for this multiphase project. Once
those are covered, Phase 1 could begin as sson as spring 2022 and Phase 2 could begin a year later.

SR99-120 Interchange Improv Proj

SR 99/Turner Road Interchange 

Measure K funding will help to make driving safer near the State Route 99 and Turner Road
interchange in Lodi. Improvements include converting a one-way street to a two-way street
and installing a roundabout to control traffic to make things safer for everyone. It is one of
several priority projects to greatly improve travel and safety along the SR 99 corridor. This is
a construction-ready project and SJCOG staff has been working to secure funding so construction
can begin as soon as shortfalls are covered.

Turner Rd Interchange 3

Stockton Diamond Grade Separation Project

The Stockton Diamond just south of downtown Stockton is the busiest, most congested at-grade
railway junction in California. There are significant delays there to Union Pacific Railroad
(UPRR) and BNSF Railway (BNSF) trains moving freight throughout the nation and it is the
worst freight rail bottleneck in the state. A freight train must stop and idle while another train
passes, causing emissions that cause air pollution. The delays also limit the Port of Stockton’s
growth and slows the expansion of the Amtrak San Joaquins and Altamont Corridor Express
(ACE) service throughout the region. The project would put the two north-south UPRR mainline
tracks on a different grade than the east-west BNSF mainline tracks, eliminating the need for the
trains to stop and idle and improving air quality in downtown Stockton. The project also calls for
bike, pedestrian, and roadway improvements at 10 local road crossings in Stockton, enhancing
safety and access for residents.


State Route 4 Extension 

Utility modifications marked the completion of the State Route 4, or Crosstown Freeway,
extension project from Fresno Avenue to Navy Drive in Stockton. This project greatly benefits
the Boggs Tract neighborhood, because it reduces highway and big rig traffic through the
neighborhood and improves air quality for the people who live there. Traffic congestion is
being reduced by improving the connection between Interstate 5 and the Crosstown Freeway
with the Port of Stockton and nearby industrial facilities helping commerce to flow freely.

SR 4

Corral Hollow Road Widening Project 

Motorists, pedestrians and cyclists will travel more safety and freely with improvements to
Corral Hollow Road. Travel lanes will be added in each direction from Interstate 580 to the
California Aqueduct in Tracy with a landscaped median and parkways, 10-foot-wide sidewalks,
new streetlights, and a four-way traffic signal at the intersection of Tracy Hills Drive and
Corral Hollow Road.

Corral Hollow