FRESNO — Roadside weather stations and sensors for traffic and fog are now in place along a 12-mile stretch of Highway 99 south of Fowler to help prevent deadly accidents in the valley's notorious Tule fog.
Information from the six weather stations, 22 visibility sensors and 41 traffic sensors will be fed to 39 electronic message signs along the highway to warn motorists to slow down in foggy conditions.
The 12-mile area extends from Fowler to just south of the Kings River, south of Kingsburg.
The California Highway Patrol and Caltrans unveiled the joint $12 million Fog Pilot Program on Thursday. The system will warn drivers that they are approaching hazardous fog conditions, officials said.
When the sensors register visibility at less than 500 feet, the message boards will alert drivers to foggy conditions. When the visibility drops to 200 feet or less, the warning will be posted for dense fog. The system is monitored at the Caltrans traffic management center in Fresno.
Even with the unseasonably warm weather this week, November is traditionally the start of the fog season, said Brian Everson, acting director of Caltrans District 6. Fog is statistically the worst weather condition to drive in, Everson said, and each year it causes accidents on Highway 99. The danger of tule fog is that it changes location and intensity.
The newly installed technology will provide "better real-time road conditions to reduce accidents in low visibility," he said.
But the true key to success, Everson said, will be if the program helps drivers be more cautious in the fog.
Said CHP commander Capt. Roy Huerta, "What you can't see can kill you."