November 23, 2012

Multiple-Car Collisions and Weather: Can We Stop the Carnage?

It has became an all too frequent news item:  dozens or hundreds of cars involved in a huge pile up on some freeway or interstate.  Dozens injured and several deaths.  Tales of terror.  Major roadways closed for extended period, with huge attendant cost.  And most are associated with a reduction of visibility due to some weather phenomenon:  heavy rain, fog, snow burst, smoke, or dust.

It happened again yesterday (Thanksgiving morning) on I10 near Beaumont, Texas and was associated with dense fog.  Nearly 150 vehicles, 2 deaths, over 50 people sent to hospitals.  Tales of screaming and narrow escape.  And such event don't have to happen.

A portion of the Thanksgiving morning I10 accident.
Such multi-car collisions have happened on many occasions here in Washington State and I believe that new weather and communication technology can substantially reduce their frequency.

First, lets talk about the "set up" for these disasters.  Generally, they occur on freeways and interstates where folks are moving fast with substantial traffic volumes.  Drivers are moving relatively close, many with insufficient following distance.  One vehicle enters a zone of reduced visibility due to one of a variety of factors:

(1) Dense fog
(2) Smoke from a nearby fire
(3) Dust storm due to strong winds over plowed, bare agricultural fields
(4) Heavy rain.
(5) Intense road glare when the vehicle exits a rain area into bright sunlight.

The driver slams on the breaks when he/she loses visibility and then other vehicles, too close to stop, crash into the first vehicle.  Vehicle after vehicle crashes into the growing pile up.

You can search news using google and bing and you will find hundreds of examples of such weather-related multiple car accidents.

How do we stop these disasters?   

 I know, a big issue is that drivers often follow too close and too fast for the weather conditions (or ANY condition).  Perhaps we need more vigorous laws about following distance and speed limits that depend on weather conditions.   It will be difficult to enforce, but I am certainly willing to see some action in this direction.

But there are some technical solutions that are possible, particularly now that we have massive amounts of weather information available, many folks have smartphones, there are reader boards and flow control on a number of highways, and soon many cars will have internet capability.

Consider an example.  There have been a number of big accident pile ups here in Washington as a heavy convective cell crossed I5 late in the afternoon.  Drivers here are used to rain, so they keep their speed up (probably too fast).  Then they exit the convective precipitation and bright sunshine reflecting off the bright roadway blinds a driver who slows abruptly.  A big chain reaction accident ensues.

We can reduce the number of these events.  We have radar imagery that can be used to predict when heavy rainfall will cross the road during the next hour.  We know where the sun is and whether clouds will block the sun.  It would be easy to determine if a risk exists or WILL exist soon.  I5 has lots of reader boards that could warn drivers to slow down-- in fact, they can even change the speed limit in real time.  This could have a huge impact on stopping such urban pile ups.  I put in a proposal to WSDOT to build such a capability...wasn't funded unfortunately.

What about smoke or fog on the roads?   We have satellite imagery that provides a real-time view of the distribution of these hazards.  Here is an example of "fog imagery) for the accident area yesterday.

And satellite imagery can show dust storms as well.  Here is one associated with a major collision event in eastern WA.

And there are huge numbers of surface observing stations located on or near highways.

 Imagine a real-time system that looks for roadway threats, sends information to all available electronic signs, and sends messages to smartphones in the area?   Folks could load a special warning app on their smartphones that would tell them when a serious threat is in front of them. (calling all weather app developers!)   Eventually (in a few years), nearly all cars will have internet capability and the warnings could be shown on the instrument panel.

There are the collision prevention systems going into high-end cars these days that monitor following distance and automatically brake the car if a collision is imminent.   That could help.  Even more futuristic we could consider having the car slow down automatically during bad weather, either from information derived from sensors on the car or information it receives via the net).   Perhaps insurance companies will give a discount to folks with this new system on their vehicle.

Bottom line:  the marriage of dense weather observations and weather imagery with new communications/control technologies can greatly reduce the frequency of multiple car pile ups...and there is a lot we could do today at modest cost.


  1. Hi Cliff. You're on target again. This is also huge in Arizona with our dust storms (both monsoon-related as well as localized gradient winds). We're working with state transport and air quality folks to come up with economical tech mechanism to address these problems. This shouldn't be that difficult!

    --Ken Waters

  2. Our GPS system warned us of traffic slow downs in Scotland in 2009. The message was broadcast even though we were playing the radio at the time. The same thing can be applied here.

  3. The Germans are probably the best-trained drivers in the world, but in 1979, I sat in the cockpit of a C-141 at Ramstein AFB, and with a good view of the nearby Autobahn while we waited for a Runway Condition Range reading for our takeoff (it was 4, too low to go, and because of the freezing rain falling, we got towed back to parking), and one of those giant crashes happened before my eyes.

    If the Germans couldn't avoid driving into a 250-car pileup, I don't see much hope here, other than by physically closing the freeways when the conditions get bad, or having travel only in piloted convoys.

    The training curve to get people to drive no faster than they can safely maneuver and stop is much too great. Robo-guided autos might help, but we are decades away from trusting them.

    Nope, this carnage is a fact of life.

    George Schneider

  4. Not so much roboguided autos, as George Schneider
    mentions, but onboard proximity detectors/sensors and a heads-up display would go a long way. I'm not much of a fan of the robot car idea, as I think we could make a lot of incremental improvements to existing cars. If cars were able to communicate their speed and maybe even their destination to each other as well display information about conditions, the vector of all surrounding vehicles and add some assistive control for accident avoidance (early braking, speed adjustments), we might see fewer accidents from carelessness.

    The intervehicle communication wouldn't broadcast your trip plans but would be more about making other vehicles are of when you might need to exit so they can make room. If A approaches his exit and B is in the righthand lane, B's vehicle might slow down just a bit if needed to allow A to exit without having make a sudden dive into the exit lane. We've all seen it, maybe even had to do it.

  5. And what about all the crashes from people looking at their phone to see what the warning is about? Such systems would need to neither distract nor startle drivers, or we might make things worse.

  6. Cliff, first I’ll offer an anecdotal story, then humbly disagree with your solution. I’ll finish with my observation regarding the story and a suggestion of my own.

    On Memorial Day 1981 I traveled down I-5 from the Puget Sound region to Portland. Mt. St. Helens had erupted for the second time in a week, spewing ash over Southwest Washington. Perhaps the most dangerous situation was where the mudflows had coursed down the Toutle River and partially covered I-5 at the Toutle River Bridge. Visibility was very obscured from the ash, especially where the vehicles had stirred it up. The Washington State Patrol used an innovative technique to enforce the 15 mph speed limit they enacted through the ash-inundated part of the freeway. They contacted truckers and set up rolling roadblocks of two 18-wheelers driving side by side at the proscribed 15 mph. All the cars on the road were forced to follow at the slow speed until the groups were through the ash. Once we were through the ash’s obscured visibility the truckers sped up, pulled over to the right lane and let the passenger cars return to the speed limit.

    While I think there is value to your ideas about increased information for drivers via smartphone, I have little faith in the skills and reasoning of most people on the road. By definition, half of all drivers on the road have below average driving skills (see, I paid attention in stats class!). Suggesting that they watch their smartphones while driving is begging for accidents from inattention. Also, we don’t do anything to improve our skills over time. Based on our current Washington State laws, it is possible to pass your drivers test then never be tested again. Personally, the last driver’s test I took was when Nixon was president. My grandmother kept her drivers license until she was 96 because she needed it for identification. Her driving skills had degraded to the point where even she realized she shouldn’t be on the road, yet could legally drive. My proposal regarding driving skills would be to require drivers to pass a skills test every time they renew their license. It would be expensive, but bad judgment is more expensive.

    My tech solution for slowing down drivers would be to institute a program using commercial drivers to create the rolling slowdowns I saw those many years ago on I-5. Install some sort of message machine (smartphone or computer) in the cab of trucks that allows the WSP to send a message to the trucker to pair up with another and slow the freeway down. Perhaps the message machine is attached to a lighted readerboard on the rear of the truck that flashes a message about the upcoming road and visibility conditions. When conditions are normal perhaps the readerboard would be available for advertising. With GPS tracking the advertising could be location based. Imagine, “Dicks drive-in, next exit” on the back of a truck. Back to the truckers, pay them a fee to train on the techniques the WSP wants them to perform then perhaps a fee every time they perform their rolling roadblocks. Looking at the pictures of the crash in Texas, I see at least a couple of trucks. If those trucks had a warning system as you suggest, they could have slowed and possibly avoided the crash. If they had a readerboard system as I suggest, they could have warned others of the impending doom.

    Using technology to make us all safer has much merit. Cliff, you have the name recognition and the influence to make these things happen. Please make it so. Thanks for being creative and caring about the community.

  7. Drivers don't slam on the breaks. If they could get a break they wouldn't have to slam on the brakes!

  8. All the warnings, signs, and advice can't stop an irresponsible driver.

  9. Excellent article. Here near to where I am more south, and if more "down the hill", within and through the greater Central Valley of CA, fog is certainly a significant problem.

  10. A plain fact of the matter is people drive in herds. They group together as if unconsciously they feel that there is safety in numbers, which at 70-80 mph is absolutely ludicrous. There are two exceptions to this rule, One: the safe individual driver, who slows down when experiencing detrimental road conditions and Two: the extremely unsafe, inexperienced, 16 year old, who has just gotten his license (to kill.) Even if we monitored, metered and put into place all the modern technology available to control the flow of traffic, people will still drive in a herd.

    Ironically the 16 year old, effectively breaks up herds by causing fear in the herd and people slow down to avoid such chaos.

  11. Not the first time. That stretch of I-10 is notorious for cool-season fog, and speeding. In the early 80s the state patrol tried to reduce the speeding with rolling roadblocks using troopers -- the letters to the editors didn't stop for weeks! But it helped, while it lasted. I like the idea of getting truckers involved -- no one else spends more time out there on the front lines, and they all have an economic interest to boot. I have seen a few of them take over and straighten out construction merge issues pretty nicely.

  12. Hopefully you didn't limit your search for funding to just WSDOT. Your odds of funding are much better through AASHTO, with WSDOT acting as your champion. In an AASHTO-funded project you might have more luck getting private-sector participation as well as state DOT partners, which is the only way you'll get the relevant information to both ITS signs and smart phones at the same time.

  13. I was thinking if there was some kind of warning system that would alert drivers in a dense fog or smoke situation it would help prevent such terrible accidents. Here is my suggestion to any that can make it work. Have a rear harmless laser light mounted on the back of vehicles that is connected to the system that controls the air bag in a collision. When the sensor goes of in a collision the laser light would strobe in some way like a head lamp on a train. The laser light would penetrate the fog or smoke and alert drivers way before they get to the accident scene. Just an idea. We could start by putting it on all commercial vehicles then all cars.


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