Here’s how California’s new ‘Turbo Roundabout’ works for big rigs

California transportation officials recently opened the state’s first “Turbo Roundabout” in hopes of reducing the number and severity of crashes.

Earlier this year, Caltrans installed a $14.6 million multi-lane turbo roundabout at the intersection of Highways 25 and 156 near Hollister in San Benito County, which experienced twice the number of collisions as similar intersections in California.

The turbo roundabout concept was introduced in the Netherlands in the 1990s. One other U.S. turbo roundabout is located in Jacksonville, Florida.

“A turbo roundabout is much like a regular roundabout but has additional safety features designed to reduce the potential for collisions, including three-inch lane dividers that guide users throughout the roundabout and discourage lane changes. Additionally, the turbo roundabout lanes have been designed to accommodate the largest trucks approved for highway travel,” Caltrans says.

Officials explained how the turbo roundabout design is meant to better accommodate tractor trailers.

“The turbo roundabout is a 2-lane design. The design reflects the need to address both traffic volumes, including truck volumes that use the intersection today and into the future. Features to accommodate all the turning movements of a tractor trailer rig are including in this design. An example of a design feature to accommodate the sweep of the trailer wheels as it makes it way through the roundabout, a truck apron (mountable truck apron) is constructed around the inside of the turbo roundabout,” Caltrans explained.

Since the turbo roundabout opened, SF Gate reports that crashes in the area have increased significantly, but that the number of crashes resulting in injury or death decreased.

Caltrans created an explainer video on how drivers can use the turbo roundabout, which you can view below.

You can click here to learn more about the roundabout project.