News: Charlotte Exclusives

Wave the Yellow Flag

Traffic safety push may have unintended consequences

Motorists in Charlotte should be on the look-out for a new-style traffic signal that is supposed to be both safer and more efficient. However, changing something so basic as the red-yellow-green rules of the road will not be easy and could prove dangerous.

Every preschooler learns the traffic light basics by just paying attention while their parents drive them around. Red means stop, green means go, and yellow means, well, yellow means either slow down or stomp on it depending on who is driving. You would be hard-pressed to find a system of rules more thoroughly ingrained into American life.

But in recent years traffic engineers have detected a problem with that system. Left-turns made on a solid green light can cause accidents if the turning driver forgets about oncoming traffic. There is also the issue of what is called the “yellow light trap” where a left-turning driver, faced with a signal that goes yellow while he or she is in the intersection, tries to hurry through the turn and into oncoming traffic that may still have a green light or is rushing through a yellow too.

The solution, the engineers say, is the flashing yellow left turn arrow. The Johnston Road-I-485 intersection was selected to receive a flashing yellow signal as part of a test by the Federal Highway Administration. The flashing yellow arrow is intended to replace the solid green light for left-turn lanes. The idea is that the flashing yellow will make it clear to left-turning drivers to proceed with caution and that they do not have a “protected turn.”

With the flashing yellow added to the mix the signal’s progression would be as follows: green arrow, flashing yellow arrow (replacing the solid green), solid yellow arrow, red light/arrow. Left turns could still be made with a flashing yellow arrow, provided no oncoming traffic is present.

But there would seem to be a problem with this new system. It is not obvious that a flashing yellow light is more permissive than a solid yellow light. Indeed, you might conclude that the flashing yellow connotes a greater sense of caution; it is flashing after all. Plus yellow lights do not traditionally convey any information to drivers about the status of oncoming traffic. Yellow traffic signals tell drivers that the signal is about to turn to red, nothing more.

Yet testimony from around the country keeps harping on the supposed benefits of the system, once the public learns it. But that is the trick, isn’t it? What if the public never truly understands the new signal, will that result in improved safety?

Indeed, the flashing yellow arrow campaign seems to illustrate crucial insights central to the work of free market economist F. A. Hayek. The first is the law of unintended consequences, where in pursuit of one government goal, a policy is enacted which actually ends up thwarting the government’s intention. A welfare system, for example, that aimed to relieve poverty, but actually punished income-production.

Similarly, traffic engineers clearly have safety in mind, but by changing a basic element of the signaling regime, the result may well be more confusion and less safety at intersections. At a minimum a serious education campaign is ahead for motorists, an added cost to the idea that should not be overlooked.

Such re-education is a sure sign some long-held societal belief is under challenge, which is another theme Hayek addresses. Traditions that are rooted in some rational justification should not be lightly tossed aside by government planners, Hayek cautioned. What Hayek called “grown law” usually represents ideas that have proven themselves over the years to work.

It is doubtful that Nobel Prize winner like Hayek had something as mundane as traffic signals in mind when making his observations, but the principles still apply. When changing the basic rules of society, extreme caution – flashing or not – should be the order of the day.