Safety
Tule Fog Near Fresno: What to Do If You're Stuck Roadside
If your car quits in tule fog near Fresno, get it out of the travel lanes first. Turn your hazards on and roll to the next exit or a business lot if the car still moves. If it won't move, pull as far right as you can. Then turn off every light except your hazards, so nobody follows your tail lights into you. If you're stuck in a live lane or anyone is hurt, call 911.
When does tule fog show up around Fresno?
The National Weather Service calls tule fog a kind of radiation fog. It forms in the Central Valley on clear, calm nights. Thick fog shows up on many nights from late October through February.
That means the worst of it hits on your early drive. You leave Clovis in the dark, and the road is fine. By the time you reach 99, the car in front of you is gone.
When fog gets bad across the valley, the weather office issues a Dense Fog Advisory. NWS says that's when you can often see a quarter mile or less. Tule fog can get much worse than that.
Can I tell the night before?
Often, yes. The NWS office for the San Joaquin Valley posts a Fog Severity Index. Caltrans says the index runs daily in winter and early spring. It rates fog by color, from Level 1 green to Level 5 purple. Level 5 means 0 to 200 feet of visibility and the biggest risk of chain-reaction crashes. Its maps show where fog should form, hour by hour, for the next 15 hours.
Caltrans District 6, based in Fresno, uses the index to put fog warnings on its electronic highway signs. Sometimes they go up hours early. So if you see a fog warning on your drive home, plan for a bad morning.
Why is a fog breakdown so dangerous on SR 99?
Speed. Caltrans says nearly three in four fog crashes are tied to drivers going too fast. On 99 between Fresno, Fowler and Selma, traffic keeps moving even when drivers can't see far.
A stopped car in that fog is a hard thing to spot. The driver behind you may see your lights only at the last second. That's why where you stop matters more than anything else you do.
Caltrans also warns that fog is local and can change fast. You can drive out of a clear patch on 41 and into a wall of gray on 99. Don't trust the first few miles.
My car is failing in the fog. Where do I stop?
Not on the shoulder, if you can help it. Caltrans tells drivers to avoid stopping along freeway shoulders in fog. NWS says to pull into a safe place, like the parking lot of a business, and stop there.
- Hazards on now. Don't wait until you stop. Drivers behind you need the warning early.
- Ease off the gas. Brake gently and early. A hard stop in fog invites a rear-end hit.
- Follow the fog line. Caltrans says to use the solid white line on the right shoulder as your guide.
- Watch for the exit break. At an exit, that white line bends right, breaks for a few feet, then runs along the ramp. Fog-prone highways also have 3-2-1 dot countdown markers before exits.
- Get past the ramp. A gas station, store lot or side street off 99, 41, 168 or 180 beats any shoulder.
Can't make an exit? Go as far right as you can. California Vehicle Code 21718 allows a freeway stop when your car is too disabled to go on and help has been called. So call as soon as you're stopped.
Which lights do I leave on?
This is the part most drivers get wrong. NWS says once you stop off the road, turn off all lights except your hazards. Set the parking brake. Then take your foot off the brake pedal.
Here's why. In thick fog, drivers lock onto the tail lights ahead of them. If your brake lights and tail lights glow, someone may think you're still moving and follow you right off the road. Flashing hazards say "stopped." Steady red lights say "follow me."
Your hazards also help you under the law. California Vehicle Code 21809 tells drivers coming up on a stopped car with flashing hazards to change lanes if they can, or slow down.
What about my lights while I'm still driving?
The California DMV handbook says to drive on low beams. High beams bounce off fog and blind you. It also says never drive with only parking lights or fog lights on. Make sure you can stop inside the space you can see.
Should I stay in the car or get out?
It depends on where you stopped.
- In a lot or on a side street: stay in the car with the doors locked. Keep the defroster going if the engine runs.
- On a freeway shoulder with a guardrail: if you can get out on the side away from traffic, wait behind the rail, well back from the car.
- On a shoulder with no safe place to stand: stay buckled in your seat.
- Stuck in a lane: call 911 right away. Don't try to push the car.
Never stand behind your car in fog. Don't walk along the shoulder to read a sign, either. Crack a window if you can. The DMV handbook tells drivers to listen for traffic they can't see, and that works while you wait too.
How will a tow truck find me if nobody can see?
By your words. In fog, your driver can't scan the shoulder for you. Give these details on the call:
- The highway and your direction, like "99 southbound."
- The last exit or overpass you passed, and the next one you think is ahead.
- Which side you're on, and whether you're past a ramp or on it.
- Your car's color, make and model.
- Anything close by: a fruit stand, a farm road, a sign, a bridge.
Then keep your phone charged and close. You'll get your driver's name and photo by text, and you can track your truck on a map. You'll see it coming long before you see its lights.
What kind of help should I ask for?
Tell us what the car did. In fog season, a few problems come up again and again.
| What happened | Ask for |
|---|---|
| Car won't start in a cold, damp lot | A jump start |
| You slid off into a ditch or soft dirt near the road | A winch-out |
| Engine died, warning lights, or damage from a bump | A car tow to a shop |
If you were in a crash, even a small one, call 911 or the police first. Then call for a tow once the scene is handled.
Who actually comes out?
Sentinel Towing is a towing and roadside network, not a tow company. A vetted local partner tow company near Fresno does the job. We text you a price first, and that price is locked before anyone is sent. Then we check on you by text until your truck arrives. That's our Stay-With-You Promise. For the freeways and neighborhoods we cover in town, see the Fresno towing page.
How do I keep a fog morning from turning into a breakdown?
- Check the fog index and Caltrans QuickMap before you leave.
- If the fog is thick, wait it out if you can. The DMV handbook says to think about putting off the trip.
- Get a weak battery tested before winter. Cold, damp mornings expose it.
- Keep your gas tank from running low. A long, slow crawl in fog burns fuel.
- Charge your phone and keep a jacket in the car.
Stuck right now? Call 1-888-TOW-1213, or request help online.
Fresno Tule Fog Questions
Should I keep my headlights on after I pull over in fog?
The National Weather Service says no. Once you're off the road, turn off every light except your hazards. Set the parking brake and take your foot off the brake. That way nobody follows your tail lights into your car.
Is it legal to stop on Highway 99 when my car breaks down?
Yes, when the car is too disabled to keep going and you've called for help. California Vehicle Code 21718 allows that stop. Get as far right as you can and turn on your hazards.
How do I find an exit when I can barely see?
Watch the solid white line on the right. Caltrans says it bends right, breaks, then follows the ramp at an exit. Fog-prone highways also have 3-2-1 dot markers counting down to the exit.
How can I tell if tomorrow morning will be foggy?
Check the NWS Hanford Fog Severity Index. It maps where fog is likely over the next 15 hours. Fog warnings on Caltrans highway signs the evening before are another clue.
Rules change, so check the official source before you rely on it. Sources: NWS tule fog, NWS fog advisories, NWS fog driving tips, NWS Hanford Fog Severity Index, Caltrans fog alerts, Caltrans fog driving tips, California Driver Handbook, California Vehicle Code 21718, California Vehicle Code 21809, Caltrans QuickMap.
