Seeing orange and white lines on the freeway? Here's what they mean

Transportation officials in Southern California are testing a new way to get drivers to slow down in construction zones, and -- based on early results -- they say it's working.

The Caltrans pilot program began on the 5 Freeway in northern San Diego County, where drivers began encountering orange and white lane striping through the Build North County Corridor Project as early as December 2021.

The $987 million project is adding carpool/High-Occupancy Vehicle lanes in both directions of the freeway between Highway 78 in Oceanside and Lomas Santa Fe Drive in Solana Beach, an area prone to heavy traffic backups.

“I was curious and didn’t know what to make of them,” said Josh Rose, who was visiting from Utah and noticed the stripes while driving from Los Angeles to San Diego earlier this month. “They certainly got my attention.”

Caltrans says the contrasting colors are designed to increase awareness of the construction zone and “enhance safety” for drivers and road crews. Officials hope drivers will not only slow down but also see the lines more clearly in the rain and fog.

So how is going so far? Extremely well, Caltrans tells KTLA 5 News.

“Recent survey data shows that approximately 83.18% of road users who traveled in the orange striping experienced increased awareness of being in a construction zone,” said Caltrans Public Affairs Manager Steve Welborn.

The survey found that 72% of drivers slowed down after seeing the contrast striping, and nearly 75% found the lines easier to see at night.

Even if he wasn’t sure exactly what the lines meant, Rose assumed they were construction-related because of the familiar color and, to that end, they worked.

“What's nice is they eliminate questions about the length of the construction zone,” he said. “Sometimes you pass all the construction, but the sign for leaving the construction zone doesn't appear until later. With the lanes changing color, there’s nothing to be confused by.”

The pilot program will continue through the completion of the North County construction project sometime in 2025. After that, Welborn says, drivers could see the lines appear elsewhere.

“Continued use is to be determined, but our goal is to implement this as a standard practice throughout the state,” he said.