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Unintended Consequences For Traffic Safety Feature
An anonymous reader writes: Traffic engineers had a problem to solve: too many pedestrians were getting hit by cars while using the crosswalks at intersections because they didn't know when the 'WALK' sign would change. Their solution was simple: implement a countdown timer. Countless cities have now adopted these timers, but it turns out to have an undesired consequence: motor vehicle crashes are actually increasing at intersections where the countdown timer is used. Researchers think this is because pedestrians aren't the only ones who see the timers. Drivers see them too, and it provides them with information on when the light will change. Then they anticipate the change by either speeding up to beat a change to red light, or anticipating a green light in order to get through before the pedestrians can move into the road. The researchers suggest finding some way to hide the countdown from the drivers, perhaps through the use of an audio countdown that would be difficult to hear from inside a car.
Please don't do an audio countdown. It doesn't work for us hard of hearing people.
Make angled sides on the signal to that you can only see it from like a +/- 5 degree angle, or less, and use sounds for the blind.
When you cant win, ad hominem.
Computers will fix this kind of thing by default.
The dangers of knowledge trigger emotional distress in human beings.
Drivers need to pay attention to the road, there is no excuse for hitting a pedestrian in a cross walk or for a car to hit car at a cross walk. Drivers need to grow up, pay attention and stop blaming everything but the lack of driving ability.
The driver should only score half points...
Worst. Signature. Ever.
In atlanta at least, the countdown is already accompanied by an audible chirp.
Intended for blind or otherwise disabled folks (except deaf folks, naturally), it also serves as a cue for regular folks as well to hurry up on some of hte larger/wider intersections.
Really all that should be fixed is to put a bigger gap between the countdown reaching 0 and the light actually changing. My experience with signal timing (and this is my trafic engineering schooling showing through) is roughly half-half: about half the intersections I saw with the countdown change immediately, others still have the standard 4-5 second "intersection clearance delay" between the countdown ending, and the light actually changing. The clearance delay exists for obvious reasons to put a delay between one side turning red and another green. It should simply also take the crosswalk into consideration as well as a best practice.
The guy who said the election was rigged won the presidency with the second-most votes.
In Ca, it's a ticket if a car enters a crosswalk while a pedestrian is using it, no matter if they're on the other side of the intersection or not. And the new walk signals have a visor around them so unless you're almost directly in front of it, you can't read it. They also started using audio signals, which beep and talk, for the blind.
...is they try to fix human behavior via engineering, but people can't really be engineered.
For example, in my home town we had a roundabout from hell. Five highways came into a loop via offramps. Literally once a week there would be an accident and once a month it was a fatal one.
So some brilliant traffic engineers tried to solve the problem by creating off ramps for each other highway. At highway A you could choose to offramp to highway B, C, or D. But the "offramps" used the roundabout, which now had concrete dividers about curb height. The mayor, the local press, and local government kept trumpeting how many lives this would save.
Well, turns out the only thing more dangerous then five highways going into a giant roundabout is five highways going into a roundabout with concrete dividers to slalom around. Accidents became a daily occurrence and fatalities went up.
As it turns out, people are stupid. Sure, if you are new to town and take the time to slow down to read the sign, and drive carefully, you can figure out where you're going. But people zip in at highway speeds, apply the brakes quickly, and try to swerve over.
The problem is not one of engineering, but one of behavior. Modifying the behavior (via police enforcement) would be more effective then a fancy solution.
A better solution might be to remove the signals altogether. Several European towns have tried shared-space experiments where there are no signals or markings and the pedestrians and vehicle drivers have to actually watch out for each other. In all such experiments so far, traffic fatalities have dropped significantly.
It has helped. Can you not read or something?
So the opposite of "not helped", it worked just fine.
However, in addition to reducing the number of pedestrian accidents it also increased the number of rear-end collisions.
Here in Bulgaria we have many (in fact, most) traffic lights with countdown timers for cars. Most don't even have timers for pedestrians. And these timers started to appear about ten years ago.
I haven't heard of increased car crashes at intersections. My own observations also don't point in this direction. People are (or at least I am) using these timers as a more precise yellow light. And drivers in Bulgaria don't have to twist their necks in order to see them. Maybe this is the problem?
Disclaimer: Bulgaria has a very high fatality rate on intercity roads. These are not related to traffic lights, though.
In some areas of Portugal we have exactly the opposite - timers applied to traffic lights instead of crosswalks. In some places we also have crosswalk timers together with traffic light timers.
Why is this a solution? Because drivers will stop paying attention to crosswalk timers and use their own traffic light timers instead, which have a security offset of 1-3 seconds. This not only makes standing at a traffic light much more dynamic and time-efficient (drivers will know how long they have to do imprudent things like fixing a rear glass, looking at the mirror, texting or picking something out of a glove box, with a high degree of safety), but it also prevents them from prematurely hitting the gas, as most drivers feel it is unsafe to go before the timer hits 0.
Also, the timer works in both waiting for a green and waiting for a red. Yellow lights could be fully substituted by a red and green light only with a timer which would turn yellow on the last 1-3 seconds before a red. It would also prevent a lot of ambiguity in yellow light ticketing which is very common in urban areas and is reason for dispute between veteran drivers and over zealous traffic authorities.
Then you also take away opportunities to be a gentleman. :(
Good. I've seen drivers behaving as "gentlemen" inadvertently cause a considerable number of near misses. Not as many as asshats cause, but quite a few. The thing is, drivers should be predictable. It might appear courteous to let someone out of a side road, but it's not usual. As soon as you start behaving differently from everyone else on the road, you cause a degree of confusion. And confusion among drivers is sometimes lethal.
So next time you're tempted to be unnecessarily courteous, don't. The driver you want to let out of the side road will get out just the same in a minute or so, and there will be reduced opportunity for confusion among other drivers around you. The most gentlemanly and considerate thing to do overall is to drive predictably, and hopefully self driving vehicles will improve that.