Diamonds — at least the diverging kind — aren’t the way to win the heart of some Manteca motorists.

They’re the ones that don’t like the first diverging diamond interchange built in California that opened 18 months at Union Road on the 120 Bypass.

The crossover weave, much like roundabouts, are a jarring departure for some. It also doesn’t help that there is the impression that the two signals aren’t synchronized as they are at the one on Highway 395 in Reno where Moana Lane traffic seems to flow in a more coordinated fashion.

And while that may be an incorrect perception especially compared to delays incurred on the Airport Way and Main Street overcrossings from traffic backed up at signals, studies conducted by traffic engineer experts in a number of states support the assertion traffic does flow quicker through diverging diamond interchanges.

It is why more than 150 diverging diamond interchanges have been built in the United States since the first one was completed in Springfield, Missouri in 2009. There are more than 80 either under construction or moving toward ground breaking across the nation. That includes two in California. One is in Ceres at Hatch Road and Highway 99. The other is at the International Business Parkway and Interstate 580 in Tracy.

Manteca, if the city realizes one of its goals, will be the first in the nation to have three diverging diamond interchanges all in a row within a three mile segment of the 120 Bypass.

Staff has already initiated planning work for diverging diamonds at Airport Way and Main Street. The first step is a pair of Caltrans Project Study reports that cost $250,000 apiece. That work will be funded by Measure K receipts gleaned from the voter-approved half cent countywide sales tax for rads and transportation projects.

As the city continues to move forward with the two interchange projects, staff recommends seeking additional funding including preliminary engineering, environmental clearance, design, and construction through 2022 San Joaquin One Voice trip next month.

The City Council is being asked when they meet Tuesday at 7 p.m. to approve lobbying for funding the two interchange projects during the trip to Washington, D.C.

The advantages of the diverging diamond interchanges include:

*Less turn movements to allow for better flow of traffic.

*Less potential conflicts to reduce the potential for collisions.

*Safer passage for pedestrians and bicyclists when it is incorporated with a separated crossing such as at Union Road that avoids crossing ramps.

*The ability to put upgraded interchanges in place without taking out surrounding development.

*A lower construction cost especially since existing bridge structures can be incorporated into the design

*Shorter construction time with less need to detour traffic.

To contact Dennis Wyatt, email dwyatt@mantecabulletin.com