I'm just surprised that there appears to have been no large interstate trucks involved.

John R. Baker, P.E. (ret)
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Someone texting while driving no doubt.

The dash-cam photo shows thick fog. When following too closely there's no time left to react.
Does anything indicate an icy surface contributed to the pile-up?

www.sparweb.ca

Crashes like this are usually associated with ice on the bridge or complete loss of visibility due to fog.

It doesn't even require texting. In the case of fog there are two separate concepts. One is to slow down to a speed that matches the visibility; the other is to not change speed at all. When those in the second group encounter those in the first or second group (not everyone goes the same high speed) then that's the seed for everyone else to slam in. Those in the first group often stop successfully for the wreckage, only to be battered by those in the second group.

And if there is ice that is in the process of melting as the sun comes up? Looks just like water and hitting a pill bug can start a spin.

There was a study done in England several years ago where, everything else being equal, it showed that people tended to speed UP when driving in heavy fog. It was shown that people underestimated the speed they were driving when visibility was limited. This was NOT related to it being dark or not. Rather it was when the ability to see a clear distance ahead of you was interfered with, such as when driving in fog, irrespective of the time of day.

John R. Baker, P.E. (ret)
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I count about 48ish vehicles in the pic. They must have towed some away already.

Good Luck,
Latexman

JR - if only there was some way to tell the speed, something a driver could look at and tell at a glance just how fast they were going. Alas this, and the mystery of what that small stick on the side of the steering wheel does and why it makes a light on the dash blink and has never stopped doing so, will likely go unsolved.

Add rubbernecking to the mix. Maybe some engineer, curious about the bridge construction between the existing roadways.

Do folks in Virginia commonly install winter tires? Temperature would have probably been in the vicinity of freezing.

I have a funny feeling that winter tires aren't a thing there.

My plan has always been: If I encounter thick fog while on the freeway immediately pull as far off the side as possible then exit the vehicle heading farther to the right over any fences. Wait for clearing or the sound of mashing metal to diminish to a distance before returning.

I have to rethink that strategy looking at this bridge mess..

Keith Cress
kcress - http://www.flaminsystems.com

Nope - winter tires are decidedly not a thing here. Last year we didn't even get snow (the bridge is a little north of me, so they may have gotten flurries once last year). Ice on the bridges isn't even a common occurrence, even with freezing temperatures. So, when you have freezing temps and thick fog like yesterday morning....nobody has the slightest clue what to do. Combine it with a narrowed bridge under construction and you have a recipe for disaster. If traffic on that stretch isn't a parking lot, it's bumper to bumper at 80mph.

Not sure you can engineer out stupidity.

This from 7 years ago.

https://www.bbc.co.uk/news/uk-england-kent-2397004...

Until all cars are equipped and run with radar and auto braking....

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

I live here. not sure if that a brag or problem. Winter tires are fairly rare and we really only get 12-20 inches of snow a year (spread over 3-4 snow falls). the construction has caused for narrower lanes and rubber-necking and it was cold temperatures over a bridge... some news reports were stating the ice caused an accident, fog limited visibility, people distracted, and then add in a two lane - no shoulder road.

From that photo, the rear dozen cars included a VDOT road side assistance vehicle (truck with a big blinky light saying move over), so it seems there may have been a crash/issue with a few cars that then grew with time and even included dispatching one of those prior to any police/state troopers. Note the cars still crashed in a 'blinky' sign, so visibility must have been bad.

If you pull off the roadway in heavy fog, turn off your lights as soon as you're out of traffic. Otherwise somebody will follow the lights. I grew up in Tule Fog country (central San Joaquin Valley) and don't miss that mess one bit.

While I've never lived in the San Joaquin Valley, I've had to drive through Tule Fog on more than one occasion and it can be very scary indeed. With the level of truck traffic on I-5 and CA-99, it's a wonder that the accidents that have occurred have not worse than they were. Speaking of the 99, my wife and I are driving up to Fresno on Christmas Day. Considering the time of year and the fact that most of the foggy areas are up closer to Stockton, we should be OK.

John R. Baker, P.E. (ret)
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John…

I live in Fresno. As I'm sure you know, tule fog is usually worst in low lying areas, particularly along rivers, creeks, and canals. The Sac-Joaquin Delta around Stockton can be particularly bad as you noted. Fortunately, fog is generally not as bad inside Fresno as when I was a kid, probably due to a combination of generally warmer winters and the urban heat island effect. Fresno was about 135,000 people when we moved here in 1963 and now it's about 500,000. Clovis has grown from about 25,000 to 110,000 in the same time. However, away from the cities, it's probably about as bad as always.

Along your route, the worst places along Hwy 99 between Grapevine and Fresno are typically the Kern River in Bakersfield, the Tule River south of Tulare, the St. John's River between Goshen and Traver, the Kings River south of Kingsburg, a low spot just north of Selma, and the San Joaquin River on the north end of Fresno. Fortunately for you, Christmas Day is supposed to be partly to mostly cloudy, so probably not foggy. You may still encounter some reduced visibility, but probably not enough to matter.

============
"Is it the only lesson of history that mankind is unteachable?"
--Winston S. Churchill

"...exit the vehicle..."

Generally not a good idea, but it depends on the cadence of the crashes.

In desolate rural areas, perhaps yes.

In areas with heavy traffic, absolutely not. Tighten your seatbelt and brace for impact. It'll happen shortly.

davidbeach; Excellent point about the lights.

I went pheasant hunting with my dad and a guy named Davey Crockett (not BS'n you either) in Los Banos by the fore bay of San Lewis Reservoir. We got smacked with heavy fog. It was so bad we had to open the driver's door and look down to see the lines on the road. We drove about 3 miles in that to a duck club turn-off. It was so bad at least no one could drive over 3MPH. Fortunately it was on a very rural road about midnight so there was no traffic at all. At least none we saw. LOL

Keith Cress
kcress - http://www.flaminsystems.com

The safest place to be is actually inside the vehicle. If you have the presense of mind wind the windows down fully so that you can get out if the doors won't or can't open.

Actually quite surprised this doesn't happen more often.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

I was almost killed in an early morning drive on a local expressway. The pavement was moist due to mist, and an unknown vehicle obviously had just spilled a small amount of oil on the pavement around a shape curve. As usual, I slowed down to make the turn, but my car spin around out of control. The lucky thing was the traffic was light, and the cars behind me were quite alert to steer clear of me.

Whether it's climate change, or whatever, I don't recall hearing about Tule fog collisions since I was a young adult. Note that I've encountered Tule fog as far south as Grapevine, but that was a long time ago. According to https://www.geographyrealm.com/tule-fog-declining-... the number of Tule fog occurrences has gone down.

TTFN (ta ta for now)
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There may be insufficient engineering; but that's due to cost. People already have a readily available indicator of their own speed; it's called a speedometer, and is usually quite visible just over the top of their steering wheels. I think the issue is that the safe speed, based on your speedometer is invariably slower than what people want to go at, particularly if you CAN'T SEE ANYTHING, so you think you;re not moving much.

I've had the occasion to drive in Tule fog and recall driving what I thought to be relatively on the edge of my visibility limit and then seeing a semi barrel past me in the fast lane going at least 30 mph faster.

TTFN (ta ta for now)
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Quote (IR stuff)

I've had the occasion to drive in Tule fog and recall driving what I thought to be relatively on the edge of my visibility limit and then seeing a semi barrel past me in the fast lane going at least 30 mph faster.

Not a semi but if it was a 5 ton it may have been me.
Many years ago I was heading east out of Vancouver Canada and the entire Frazer Valley was blanketed in thick fog.
The car drivers had almost zero visibility.
The thing was that the fog was only about 4 or 5 feet thick.
The car drivers were right in the thick of it.
In the truck cab, we were above the fog in clear air with excellent visibility.
We could just see enough of the road to drive fairly fast and the tail lights of the cars let us easily avoid the very slow and very sparse traffic.
I did wonder what the other drivers thought when we barreled past.

Bill
--------------------
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I don’t know if the San Joaquin Tule Fog was ever only six feet thick, but I’m sure there were many times it was less than twenty feet thick.

I've driven in fog when it was only about three feet thick and it's a very weird sensation.

John R. Baker, P.E. (ret)
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BTW, we made it to Fresno with no problems and no fog. Christmas Day traffic was very light. I don't think I've ever seen LA traffic as light as it was yesterday, but then I've never driven thru LA on Christmas before.

John R. Baker, P.E. (ret)
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"I've never driven thru LA on Christmas before."

That's true of most people, which is why traffic is so light, and also why most people are unaware it is so light on Christmas day. One year I tried to buy some milk on Christmas day in Lakewood. Until then I never realized how few stores are open on Christmas. I found some milk at a small liquor store.

Some supermarkets are open on Christmas day, as are some pharmacies. I nearly made a trip to the local CVS yesterday to try and find a faucet aerator tool, but luckily, managed to find one in one of my many boxes. As it turned out, that wasn't where the problem was, anyway.

TTFN (ta ta for now)
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Christmas is over, can we get back to the focusing topic - some sort of "Engineering Failure" :)

Yes, our local Ralphs was open yesterday (I saw a sign a couple of days ago).

Twenty years ago my wife and I visited our son and his family for Christmas, who had just moved to Houston. We got there Christmas Eve and the next morning we discovered that they barely had any food in the house and we went looking for a store to be open and there was nothing. We finally found a gas-station mini-mart where you had to pay three-prices for a bottle of milk and some lunch meat and bread.

John R. Baker, P.E. (ret)
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@r13 don't be a Grinch

Besides, this is mostly a people problem; until such time that all cars are autonomous, have radars and automatic following/braking, such incidences aren't going away. The bad news will be that the radars will insist on a much wider gap between cars, which we won't stand for; not following 15 ft behind a car going 85 mph is just so un-American...

Actually, the gap might not be THAT large, assuming the cars can also coordinate amongst themselves; if there's intra-car comms, the first car to see the fog can relay warnings to all the cars following, resulting in much better behavior than each car individually finding out about the fog.

TTFN (ta ta for now)
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Quote:

just so un-American...

:) Something to think about!

Had a hypothetical family stayed in the white SUV they would all have been severely injured - distance from the road > remaining in the vehicle. https://twitter.com/KCBD11/status/1210679686491246...

We start back to SoCal from Fresno in the morning. We lucked-out driving up here on Wednesday as they closed the Grapevine about six hours after we had passed thru the area (the I-5 remained closed for about 36 hours). As for tomorrow, it appears that we should be OK going up the Grapevine (they're predicting the next heavy snow there starting Sunday afternoon) however, we might see a bit of that Tule fog in the morning as we're leaving Fresno.

John R. Baker, P.E. (ret)
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Geez Dave! That video is hideous!

Clearly or foggily, there needs to be a protocol for fog. Having dozens of emergency responders, who obviously took time to accumulate, only to become potential bowling pins is moronic! The highway patrol should've blocked any further traffic into the area before anyone was at the scene.

Also, don't trip while running out of the path of a careening semi.

Keith Cress
kcress - http://www.flaminsystems.com

I like to keep eyes on at least two cars in front of mine, and one direct behind, in case the leading one makes sudden stop and causing a pile up accident. However, it is often impossible in thick fog, or heavy snow storm situations, and I do have a tendency to follow and chasing the tail lights in front of me, that renders not enough safety distance between us. I found the best way is just pull over, stop, keep engine and warning lights on, then have a little rest while waiting.

Quote (retired13)

I like to keep eyes on at least two cars in front of mine, and one direct behind

Same here. I will adjust my distance to the car in front depending on both the closeness of the two (or more) cars in front of me and the car in behind me.

Of course this does end up angering some idiots behind me as the closer they get to you to bigger gap I have to leave to the cars in front. But hey, I'm not putting myself in the middle of a stream of cars with a quarter of a second gap between each car.

Our drive home yesterday went off without a hitch. The morning 'fog' in Fresno turned out to be just a bit of mist in the air by the time we hit the road. There was a lot of snow at the top of the Grapevine, but it was all off the road where it was just nice to look at. BTW, we had a great time at our granddaughter's house and got that rare four-generation photo:


December 2019 (Sony a6000)

That's John Jr, Tyler, Marina, John Sr and Barbara.

John R. Baker, P.E. (ret)
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