In a Chain-Reaction Pileup, What Happens to Your Claim?

Tule fog is the one California driving hazard that regularly turns a two-car crash into a twenty-car one. The danger is usually not what sits in front of you. It is the closing speed of everything behind you, arriving into a wall of white at whatever felt reasonable a mile back.

What tule fog actually is

It is a ground fog, not a coastal one. It forms in the San Joaquin and Sacramento valleys on still, cold nights after the ground has taken on water from winter rain, and it settles into the low ground between two mountain ranges because there is nowhere else for it to go. It is a winter phenomenon, usually thickest in the hours around sunrise, and it is named for the tule reeds of the valley wetlands. What makes it dangerous is not its average density but how fast that density changes: a quarter mile of visibility can drop to three car lengths in the distance it takes to cross one overpass, and nothing warns you first.

Why it produces chains of cars instead of single crashes

A pileup is a speed-differential problem. The first driver slows — correctly — to something that matches what they can see. The driver behind is still carrying the speed that felt fine thirty seconds ago, picks up those taillights far later than they would in clear air, and arrives with no room. Now two stopped vehicles occupy a lane inside a bubble nobody can see into, and every car that arrives after that has a shorter margin than the last. That is the entire mechanism, and it is why the sequence keeps running long after the original crash is over.

Vehicle Code section 22350, the basic speed law, is written for exactly this situation: no person shall drive at a speed greater than is reasonable or prudent having due regard for weather, visibility, and the traffic on the highway. The posted number on a valley freeway is a ceiling for clear conditions, not an entitlement in fog.

Lights: what the law requires, and what actually helps

Section 24400(b) requires at least two lighted headlamps during darkness or inclement weather. Subdivision (c) defines inclement weather two ways: a condition that keeps you from clearly discerning a person or another vehicle at 1,000 feet, or a condition requiring continuous windshield wiper use because of rain, mist, snow, fog or other atmospheric moisture. A normal December morning in the valley satisfies both.

• Low beams, not high. High beams bounce off suspended water and put the light back in your own eyes. If the road looks worse after you switch them on, that is why.
• Fog lamps if the car has them. They sit low and throw wide, which is the right shape for a layer sitting on the road surface. Many cars do not have them at all.
• Daytime running lights are not headlights. On a lot of vehicles they leave the tail lamps dark, and being seen from behind is the half of this that matters.

If you have to stop, get all the way off

Stopping in a travel lane is the single act that converts two vehicles into twelve. Get past the fog line and as far onto the shoulder as the ground allows, then get people out on the side away from traffic and move away from the car. In our office the calls that end worst are almost never about the first impact. They are about someone who was standing next to their vehicle afterward.

What the claim looks like afterward

Multi-vehicle fog crashes settle more slowly than ordinary ones, because fault has to be worked out impact by impact and drivers routinely disagree about the order things happened in. Two practical consequences follow. First, if you carry collision coverage it can start your repair while liability is still being argued, which in a twelve-car claim can be the difference between weeks and months. Second, uninsured motorist coverage matters more here than usual, simply because the more vehicles in the chain, the better the odds that one of them has no policy behind it. Insurance Code section 11580.2 requires uninsured motorist coverage to be offered with a liability policy, and it can only be deleted or reduced by a written agreement in the form the statute sets out. If you do not remember signing one, you may well still have the coverage — worth confirming before fog season rather than during it.

Ask us to price collision and uninsured motorist side by side so you can see what each one actually changes for you.