The City of Manteca is working
with Caltrans and SJCOG to improve safety at the interchange of Union Road and
State Route 120.
This will be 1st Diverging Diamond Interchange (DDI) in California.
City of Manteca in partnership with Caltrans District 10 and SJCOG are working
to improve safety and traffic flow at interchange located at State Route 120
and Union Road.
The project will improve safety conditions by constructing new on &
off ramps, widening Union Road to 4 lanes between Daniels Street and Lifestyle
Street and will provide a Class I shared use path and Class II bike lanes.
The new interchange reduces conflict points between vehicles
and moves traffic more efficiently through the interchange. The DDI is unique
in that traffic on the local road is shifted to the left side of the road,
before being shifted back to the right. Eliminating any left hand turns through
the intersection. Upgrading to the unique
DDI configuration provides significant cost savings and safety benefits for
both vehicles and pedestrians.
Union Road is a key crossing of State Route 120 in the
City’s bicycle master plan. The new Class I path will provide a 12-foot wide
grade-separated trail that eliminates all bicycle/vehicle conflict points
within the interchange to provide safe and efficient passage for bicycles,
pedestrians, and other non-motorized travel.
Benefits of a Diverging Diamond Interchange (DDI)
Cost effective solution allows for the project costs to be greatly reduced compared to other interchange types. This also allows for the existing bridge to remain.
Improved traffic operations on Union Road. This project will also construct auxiliary lanes on State Route 120 from Airport Way to Main Street.
Compact footprint by eliminating right of way acquisition.
Class I grade separated shared use path improves pedestrian and bicycle mobility. This accomplishes the City's General Plan goal and closes a significant gap in the pedestrian network.
Safety is highly increased with a DDI. There are reductions in collision points and added safety to bicycles and pedestrians.
Key Project Elements
- Provide Pedestrian Access
- Reduce Traffic Congestion
Safety is a priority.
This Diverging Diamond Interchange will reduce
the number of conflict points from the existing 26 down to 14. Most importantly, the more severe collision
types (crossing/T-bone) are reduced form 10 down to two.
The existing overpass does not have designated pedestrian or bicycle access. The new interchange will and provide a Class I shared-use path and Class II bike lanes. The new Class I path will provide a 12-foot wide
grade-separated trail that eliminates all bicycle/vehicle conflict
points within the interchange to provide safe and efficient passage for
bicycles, pedestrians, and other non-motorized travel. Auxiliary lanes will be constructed between Airport Way and Main Street on eastbound and westbound State Route 120
City of Manteca
San Joaquin Council of Governments (SJCOG)
Shared Funding for this project is provided by City of Manteca and SJCOG.
|June 25, 2019||Groundbreaking Event|
|July 9, 2019||Construction Begins|
|End of 2020||Projected Completion|
Work will generally take place between 6 a.m. - 5 p.m. Monday through Friday. Night and/or Weekend work may occur as necessary
Traffic Detours and Closures will be posted in advance on the City of Manteca Website Project Page and the City of Manteca Facebook Page.
CONSTRUCTION BEGINS JULY 8, 2019
Weather permitting, SR120/Union Rd Interchange construction will begin Monday, July 8th. We are expecting recurrent lane/shoulder closures and one lane reversing traffic control in the project area. The lane closures will continue intermittently throughout the 1-year construction and will typically take place between 6:30am and 5:00pm Monday through Friday, with the full roadway being re-opened each afternoon. Emergency vehicles will be allowed through the construction site and we will have a plan for traffic control personnel to follow in the event that these vehicles need to pass through during the lane closure.
Project Manager: Koosun Kim email@example.com
Main Office Line: 209 456-8400