Even though it looks like something Hot Wheels would have designed, the diverging diamond interchange is actually expected to make the Union Road interchange safer.
MANTECA, Calif. — California’s first diverging diamond interchange (DDI) has finally debuted in Manteca.
Other states, like Nevada, have already installed a number of these unique designs over the years, but Manteca just cut the ribbon on on California’s first. That being said, drivers will still have to wait until Nov. 25 before they start cruising through it.
Its innovative design might look intimidating, but it’s meant to make traffic more “stop and go” for people crossing Union Road at Highway 120.
“I think that they’re going to be very happy with what we’ve provided them and it’s going to increase operability, and throughput and potentially capacity down the road…,” said Rob Shackelford, an engineer on the project with Dewberry.
Adding onto that, traffic safety takes a step up by reducing the potential accident locations from 26 to 14. Shackelford said there’s less opposing traffic and less opportunities for a T-bone style crash.
“With the diverging diamond, you’re not getting those,” he said. “Yes, you’re coming in and you’re merging at a lot of different locations, but you’re not getting those severe opposing angles of attack between two vehicles.”
The design is also safe for pedestrians and bicycles with a 10-foot-wide trail within the interchange that limits how many times they’ll interact with a car.
In the simplest terms, a DDI has drivers enter from the right side of the road, cross to the left side as they go through the interchange, and cross back again to the right.
This crisscross pattern keeps traffic moving through the intersections and provides free left-hand turns for drivers heading on and off the freeway.
It might look confusing, but the concept is fairly simple. If you want to make a left-hand turn at the interchange, stick to the left lane and you’ll get a free left-hand turn. If you want to make a right-hand turn, stick to the right lane and you’ll get a free right-hand turn.
“If you’re an attentive driver and you understand the rules of the road, you should be able to navigate this no problem, but you need to abide by the rules of the road so to speak,” Shackelford said.
