BIG SUR — When the next major storm hits Monterey County, Caltrans will take a proactive safety approach by shutting down Highway 1 along the Big Sur Coast at two trouble spots.

Gates have been installed at Mud Creek, where more than 5 million cubic yards of dirt and rocks slid down the hillside and covered a quarter mile of the roadway with as much as 40 feet of debris in May 2017, and at Paul’s Slide.

Susana Cruz, a Caltrans spokeswoman, said continued slide activity at the two sites combined with the multiyear process of the earth beneath Highway 1 at Mud Creek settling led to the decision to shut the road to all traffic as major storms approach.

“We don’t know how that’s going to pan out,” she said of the dirt and rock settling beneath the highway.

Highway 1 at Mud Creek, about 9 miles north of the San Luis Obispo County border, reopened July 18 after a $54 million project to build the road on top of the rocks and dirt from the slide. At the time, Cruz said it would take two winters before the earth beneath the highway settled. Small cracks appeared on the road in August due to the settling process.

The National Weather Service will provide Caltrans with specific forecasts for the area of the slides, Cruz said. Caltrans will send out a public 48-hour traffic advisory when major storms are in the forecast. Caltrans District 5 Director Tim Gubbins or the California Highway Patrol will the make the call about a day before the storm approaches to close the highway.

“We want to give the locals, people with reservations or anybody wanting to be on Highway 1 with that opportunity to allow for prep work or stocking supplies, getting their generator in order or to make other plans,” Cruz said. “We want people to be alert.”

At the 24-hour mark, Caltrans will send out a traffic advisory either confirming the full closure or providing more information. Mud Creek and Paul’s Slide, about 13 miles north, will be treated separately. meaning one site may close while the other does not. Signs alerting motorists to potential closures will be posted in advance.

Nobody, including first responders and Caltrans employees, will be allowed through the gates. Cruz said Caltrans has been in touch with emergency service officials in the area and plans are in place in case anything happens during the closures. The closures will last at least overnight.

“First thing in the morning, our geologists will be up there to determine how safe it is even to clear the roadway,” she said.

The closures will last until conditions are safe.

Caltrans closed Highway 1 multiple times during the winter of 2016-2017, including the eight-month closure due to cracks in the Pfeiffer Canyon Bridge caused by a slide underneath.

“The locals know that there are many, many slides along Highway 1, hundreds of them,” Cruz said. “Some are active, some are dormant, but right now the two that are more active and more visual are Mud Creek and Paul’s (Slide). But two winters ago we had many different slides take place.”

Caltrans completed work on a retaining wall last month at Paul’s Slide, near Limekiln State Park. Highway 1 at the slide suffered major storm damage in January 2017, losing part of its embankment including the southbound lane and closing for several months.