I received the following email from Helwig Van Der Grinten, who left a comment on this post. I thought it was worth sharing and commenting on.
In the discussions about red light cameras I’ve read in your blog and elsewhere, it seems that everyone is ignoring the fact that all drivers must make a snap decision when a light changes from green to amber. Cameras do nothing to help a driver make a correct one. They merely penalize an incorrect guess.
According to a report of the Virginia Transportation Research Council published in January 2005 (http://www.thenewspaper.com/rlc/docs/05-vdot.pdf), of 33,547 citations (I added them up from Table 8) issued for red light violations a very large majority (85%) were issued for vehicles that entered the intersection within the first two seconds after the light turned red. This indicates that a vast majority of red light violations were not deliberate. Most violators are just poor at judging the how much time they have before the light turns red. The report also indicates that the number of citations decreases after the cameras have been in place for a few months obviously because the risk associated with a driver’s bad guess has increased by the threat of a ticket. Unfortunately, the incidence of rear-end collisions also increased because inexperienced drivers are more likely to jam on the brakes in a panicked effort to avoid getting a ticket. What is lacking is a clear way for drivers to make a correct decision to either stop or go when seeing a green light turn amber.
Here is a simple solution to this problem. This will enable a driver to accurately judge both time and distance so that there will be no doubt about whether he or she should continue at the speed limit or come to a stop when seeing a green light turn amber.
It’s in two parts. First, the amber time must set be in accordance with the formula agreed upon by traffic engineers that pegs amber time to the speed limit and the slope of the road at the intersection. The higher the speed limit and the greater the down hill slope is, the longer the amber time should be. The formula even allows one second reaction time for a driver to realize he or she should stop. Secondly, taking this standard amber time into account, it is simple arithmetic to calculate where a yellow stopping distance line should be painted across the road. This line would indicate to a driver who sees both an amber light and the yellow stopping distance line ahead that he or she should use a normal braking rate to stop at the intersection. If the driver sees that he or she is beyond the yellow stopping distance line when the light changes form green to amber, it is safe to proceed through the intersection at the speed limit and not run the risk of violating the red light.
I propose to found “The Houston Coalition Against Red Light Cameras” to promote this solution and to oppose the unfair entrapment of innocent drivers that is now being perpetrated by all of the proponents of red light cameras.
Lets put an end to the time and distance game that all drivers are forced to play with all the odds stacked against them. STOP THE PHOTO-RED SCAM! What do you think?
I think Helwig is far more lenient on red light runners than I would be. I very seldom find myself in a position where I’m not sure whether I should brake or accelerate when a light turns yellow; the times when I do, it’s usually because I’m going faster than I should. I don’t think this is a “guess” that people are making, I think it’s plain old impatience. Believe me when I say I have a lot of sympathy for that particular emotion, especially when driving. But if we all did what they taught us in Drivers Ed (and which they reinforce ad nauseum in Defensive Driving classes, a curriculum with which I’m familiar thanks to that impatience I mentioned previously) and made it a habit to slow down and be prepared to brake when the yellow light appears, we wouldn’t be guessing and we wouldn’t be running red lights.
I don’t think it’s a surprise that most red light runners do so within the first two seconds of the light turning red. I mean, when else would it happen? This is like saying that most speeders are caught doing less than 15 MPH above the limit. I don’t buy the argument that these are not deliberate. Have you never hit the gas to make it through the light before you lose the yellow? I’d bet that’s what a lot of these folks are doing.
That said, I’ve no quarrel with the suggestions Helwig makes. By all means, optimize the yellow light times, and paint yellow stopping distance lines (I’m more skeptical of these, as stopping distance is a function of speed, which is not going to be a constant at these intersections). I’d go farther and say let’s make sure every camera-enabled intersection has Walk/Don’t Walk indicators as well, since they provide an extra measure of how much time you have till the light turns on you. Heck, I’ve even seen them with timers, counting down the seconds in the cycle. You can even add signs warning people about the presence of the cameras, which some people are oddly enamored with, if you think they’ll do any good. If all that will help, I say go for it. Use the revenue from the tickets generated to pay for any extra hardware needed.
If we do all that – if we make it as easy as possible for people to determine when they need to stop for the light and what will happen to them if they don’t – can we then agree that the argument about red light cameras being nothing but revenue generators are no longer valid? I mean, at some point, we have to agree that it’s illegal to run a red light, and that there may be consequences for doing illegal things like that. Right? Look at it this way: if all these enhancements really do cut down on red light running, then the cameras won’t be such a gold mine after all. It’s a win-win.
Believe it or not, I still haven’t made up my mind about these things. I’m still not impressed by the revenue arguments about the cameras, and that seems to be the main point being brought up by their opponents. My concern is still about how the image data is stored and used, and what benefit (i.e., reduction in fatalities and serious injuries) we’re getting out of all this. I’m still waiting to see some data from Houston’s implementation. I’m perfectly willing to tinker with that implementation to address other concerns, but I see all that as a sideshow. This is what I want to know, and I hope we’ll know it soon.