Manteca is about to set a new standard for California that’s long been dubbed the “Land of the Freeways.”
Mayor Steve DeBrum pointed to Manteca breaking ground later this year on the state’s first diverging diamond interchange at Union Road and the 120 Bypass during Wednesday’s State of the City conducted by the Manteca Chamber of Commerce at the Manteca Transit Center.
The interchange design reduces construction costs significantly, eliminates a number of traffic signals to improve traffic flow, and also increases safety as the 200 diverging diamond interchanges in place elsewhere in the country have been shown to reduce accidents.
DeBrum lauded staff for innovative thinking as well as their successful effort to secure federal and state funds to complete the $21.2 million project. By pursuing a design that did not require a full cloverleaf, staff was able to eliminate the need for costly land acquisition, the existing bridge could be used, and reduce the timeline needed for construction. Cost avoidance has been pegged at nearly $10 million.
The diverging diamond design calls for traffic lanes crossing on either side of the bridge structure so northbound traffic would cross the bridge on the west side instead of the east side with the southbound lanes on the east side instead of the west side. Once they clear the bridge they are switched back.
The on and off ramps along with the flipping of the lanes creates two semi-diamond shaped intersections on either side of the bridge. This eliminates the need for traffic from both directions on Union Road as well as that coming from the 120 Bypass to avoid needing any traffic signals to exit an off ramp or to get into an on ramp.
Benefits listed by various state Departments of Transportations across the country include fewer conflict points, better sight distance at turns, virtually no driver confusion (based on a federal study), and wrong way entry to ramps is very difficult.
At the same time Manteca is building a separate bridge crossing for pedestrians and bicyclists using Measure K gas tax funding to enhance their safety and further improve what traffic signal movements there are as part of the design.
The mayor also referenced six city street projects costing a combined $9.2 million that are in line to be completed by the October.
upavement maintenance work on neighborhood streets bounded by Crom Street to Louise Avenue and Airport Way to Union Road. Work will start in April
upavement maintenance work on neighbored streets bounded by Union Road, Louise Avenue, Main Street, and Yosemite Avenue. Work will start in May.
uMain Street rehabilitation from Atherton Drive to Center Street. Work will start in July.
uYosemite Avenue rehabilitation work from Main Street to Cottage Avenue. Work will start in August.
uRehabilitating streets with pavers in Springtime Estates bounded by Louise Avenue, Main Street and Highway 99. Work will start in September.
uRehabilitating streets with pavers in Mayors’ Park bounded by Louise Avenue, Union Road, and Union Pacific Railroad. Work will start on September.
In addition, $1 million will be spent along Woodward Avenue to replace inground flashers with overhead flashers at the Wellington Avenue crosswalk, install a three-way stop at Pillsbury Road with an overhead red flashing light, and place overhead flashers at the Pagola Avenue crosswalk similar to what is in place at Buena Vista Drive and what will go in at Wellington Avenue.
DeBrum also pointed to other projects that will continue to move forward including work to allow ground to break on the McKinley Avenue and 120 Bypass interchange in 2019.
Editor’s note: Saturday’s State of the City story will focus on public safety.