Friday, 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.



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