Possumblog

The Road to Hell...

...apparently has painted dots spaced 80 feet apart. In yet another one of those 'law of unintended consequences' moments, we have this from the great state of Washington: Washington: Attempt to Stop Tailgating Causes Massive Traffic Jam

An attempt by Washington state transportation officials to stop tailgating failed an important reality test over the weekend when it caused massive traffic jams on a two-mile stretch of northbound Interstate 5. Officials had just unveiled the "2 dots 2 safety" program that urged motorists to keep no less than two of the specially painted freeway pavement dots -- 160 feet -- distance from the car in front. Each dot is spaced eighty feet apart on the freeway between Lacey and Nisqually.

Awwww--good intentions! My only surprise is that no attempt seemed to have been made to say the program was For The Children^tm. Anyway, back to good intentions...

The hope was to expand the program statewide and use the dots eventually to help police issue $101 citations to drivers for following too closely.

Yep, nothing like setting up a nice little revenue enhancement scheme to make everyone feel good about themselves. IT'S FOR THE SAFETY!

During heavy Saturday traffic, however, motorists maintained the 160-foot distance as required by the posted signs, even though such distances were unnecessary at the crawling pace. This further reduced the freeway's capacity causing a chain-reaction slow-down.

"The idea was not to impede traffic, but to increase safety," state Traffic Engineer Ted Trepanier said in a statement provided to The Olympian newspaper. "We apologize for delays drivers faced as a result of this program."

To their credit, they recognized the boneheadedness pretty quickly. However, statistics and a credulous press enter the picture, and you can pretty much guess how that turns out:

The state maintains tailgating is a problem because it leads to rear-enders. "Twenty-one people died in rear-end crashes in Washington during 2005," the Washington State Department of Transportation (WSDOT) website asserts.

Okay, following too closely is inherently a bad idea, and it can lead to rear end collisions if the following vehicle can't stop in time. But the raw number of fatal rear-end collisions cited does not necessarily mean that tailgating is necessarily the cause, nor that dot painting was the way to solve the problem.

First, where did the fatal rear end collisions occur? I don't have any idea, but it would be nice to know how many occurred on Interstates versus surface streets or rural roads, because in general Interstates are much safer than any other type of roadway, and although it may seem counter-intuitive (you know, since "urban" = "scary") urban Interstates are safer than rural ones. And what about such things as the day of the week, the time of day, and the weather? It's much less safe in the dark, or in the rain or snow, and in the dark rain and snow is even more scary. Especially on a rainy snowy dark Saturday night! So, it would be nice to know a bit about that as well.

Second, of the collisions that occurred on Interstates, how many were actually the result of following too closely, versus those caused by inattention to stopped traffic ahead? Because if you think about it, if you're following too closely behind another moving vehicle, the net difference in speed between your two vehicles isn't nearly so great (and potentially fatal) as it would be if you're off wool-gathering at 70 mph and decide it might be a good idea to see where you're going, only to find that you have sped up onto a line of traffic at a dead stop. I'm willing to wager that a goodly portion of those fatalities probably involved something other than simply following too closely.

Third, of all the rear-end collisions, exactly how many occurred due to impairment on the part of the following driver? Seeing as how about 40% of all traffic fatalities are the result of someone driving while under the influence of something, could it be that 8 of those 21 deaths were by someone so hammered that painted dots on the roadway would have been meaningless? Maybe.

Fourth, 21 compared to what? Is this an increase, or a decrease in the number of deaths? And more importantly for the way in which statistics are kept, is this an increase or decrease in the rate of fatalities? That is, the amount of fatalities for a given amount of miles traveled. Because just about every set of statistics released by the Feds has shown a decline in Interstate traffic deaths per 100,000,000 miles traveled for almost every year of the past forty. Despite everything, it's actually safer to travel by Interstate now than it every has been.

Fifth, if we take Washington's rate and compare it to that of other states, is it higher or lower? Although there's nothing inherently wrong with trying to make travel safer, if it's already ahead of the average, it might be worth considering another avenue (so to speak) where funds could be more efficiently allocated. According to this table, the U.S. rate of fatalities is 1.4 per 100,000,000 miles traveled. Washingtons seems to be doing something right already, as their rate is only 1.0. Us po' slobs down here in Alabama are offing ourselves at a rate of 2.0 per 100M. (And as always, we say thank heavens for Mississippi, who come in at 2.3 per.)

If you take all that into consideration, it is possible that the good citizens of Washington might be being squeezed by some overzealous--although well intentioned--folks who just want to do what's right. Or not.

In the context of red light cameras, however, Washington state dismisses the importance and severity of potentially fatal rear end collisions and encourages cities to install the automated ticketing systems.

Well, there IS that whole revenue thing again, isn't there? As my good friend Fritz Schranck notes, there are some valid reasons for a municipality using these cameras as an aid to law enforcement, and they don't necessarily lead to higher numbers of rear enders (especially if the yellow light interval is lengthened enough to give ample warning of change to red).

However, in practice, there IS a lure out there and there ARE jurisdictions who see things such as red-light cameras as well as all these other sorts of putative safety programs (which are invariably run by private contractors who take a cut of the money and give a bit back to the public coffers)--as nothing more than a way to pay lip service to safety, while tapping a previously unplumbed source of cash. It also doesn't help when the politicos take advantage of the fun offered by the lobbyists representing the companies who install and maintain traffic cameras and issue the tickets.

Although it might be difficult to believe, it's almost as if some lawmakers are being somewhat misleading about their true intentions!!

Yes, I know! Shocking!

Anyway, at least we can again applaud the folks up in Washington for seeing this was a bad idea and stopping it. Right? Well, maybe not.

WSDOT will now remove the dots from I-5 and try them on another freeway.

Imagine that.

Now then, if you want to REALLY do some good, do something for me. Learn to drive.

Be aware of your surroundings and alert to potential danger from other drivers.

Be confident in your abilities and the capabilities of the vehicle you're driving.

Understand the effects of such things as weather or your own physical condition can have on your reaction time.

Rather than trying to gauge a particular number of feet, try to maintain an adequate cushion based on your time interval between you and the car ahead of you. The old "two second (and more as conditions dictate) rule" serves well, and has for many years--if you use it.

Update--I note that the "time of day and road condition" table gives the percentage of accidents, not a rate. Obviously, more accidents occur when it's light, because most travel occurs when it's light. I have not been able to find a table showing the rate per mile driven at specific times or conditions is higher at night or in foul weather, but if there's a stat to be gathered by the Feds, I feel certain it's out there somewhere. If you run across it, let me know.

It does serve as a point of discussion, though, about reading statistics--some might see the large percentage and suggest that if so many fatal collisions occur during the day, wouldn't it make sense to outlaw daytime driving? It's a bit like the old joke about the guy who found out most fatal accidents occur within five miles of home, so he moved to a new home ten miles away from his old one.

Posted by Terry Oglesby at August 17, 2006 11:57 AM