My attention has been drawn to a video from the U.K. that advocates removal of traffic signals.
I am sure that removing traffic signals is sometimes beneficial — my late friend Gihon Jordan pioneered it in Philadelphia, and he was able to report reductions in crashes. He did a careful survey of crash data to confirm that result.
On the other hand, in many situations, removing signals will not improve safety and mobility, or it must be accompanied by other changes (such as conversion of intersections to roundabouts) if it is to work.
My point in writing this, though, is not to try to evaluate the practice, or the particular intersection shown. Rather, I want to point to a style of advocacy. The video shows some heavily-edited clips of congested traffic before the signals were removed — and free-flowing traffic after, but the video consists mostly of a series of testimonials. There is only one statement by an engineer who might have the technical background to evaluate where traffic-light removal might be suitable. The remaining statements are by ordinary citizens with no particular technical expertise, including two groups of schoolchildren. The video casts the traffic-signal industry as an evildoer by implying that it is unduly influencing design choices, a statement which the video does not support with any evidence. There is some narration to the effect that accompanying measures are needed, but this is given way too little time to explain such issues adequately. Only one negative opinion is represented, from a blind man who, understandably, has more trouble with uncontrolled intersections than with signalized ones.
Traffic engineering has been subject to political pressure as long as it has existed, and with very mixed results. To be sure, we wouldn’t have infrastructure for travel if the public didn’t agree to fund it, but then, there is a strong element of tragedy of the commons in the uneconomical use of clean air and of subsidized infrastructure. Dominant modes of transportation — railroads in the 19th century; private motor vehicles and commercial air travel in the early 21st, — distort transportation choices — by making streets less hospitable, by taking the lion’s share of public funding, by reducing demand for other modes so they become less economical, by affecting patterns of land use. A full-cost, pay-as-you-go model would not be practical, because so much infrastructure must be held as a public monopoly: there can be only one set of streets, one urban public transportation system, etc. and it must be accessible to people at all income levels.
While political pressure is unavoidable, appealing to the general public for implementation of a specific measure has its perils. Where infrastructure choices are driven by such advocacy, the results often are out of tune with best practices as established by careful analysis. Common examples are demands for more traffic lights or stop signs — or, getting around to the topic of bicycling advocacy, for special bicycle facilities as if they were some kind of panacea. It is too easy to push for simple solutions to complicated problems.
And also as to bicycling, here’s one specific I noticed in the video: there’s not one single bicyclist in it, from beginning to end. I think that deserves mention. I don’t know whether bicyclists were there but were intentionally not shown, or whether there just weren’t any. In either case, I regard that as unfortunate and I’d like to know why!
