One of the most sophisticated highway fog detection and alert systems in the country is now set to activate automatically.
This is the fourth year the Caltrans Fog Pilot Program has been alerting drivers about fog on Highway 99.
The system is designed to automatically display roadside messages about fog and traffic when it senses trouble.
Along a 12 mile stretch of SR-99 from Fowler past Kingsburg, the project has more than 40 traffic detection systems, two dozen visibility sensors, 6 weather stations and more than 40 electronic display signs.
The area was chosen because of several deadly multi-car pile-ups that have happened due to fog in the past.
Fog can be light in some spots, and very thick nearby. Dense areas move and change quickly, so the system monitors a dense network of sensors constantly.
Signs not only warn drivers of dense fog ahead, but show what speed traffic ahead is going.
Drivers on all roads are encouraged to slow down when driving in fog.
Fog-related accidents carry the highest fatality rates.