It is strange just how easy and quick it is to get used to something, such that it is a bit of a shock when one does not see what one has become accustomed to. An example of this phenomenon for me is the flashing yellow left-hand turn light. I had never seen this particular light before moving to the Portland area, but it can be found on many streets (especially those whose lights are fairly new) in the metropolitan area. It did not take long at all (less than a few months, which is all the time I have spent here so far) for me to expect to see them.
This has consequences that are sometimes humorous, especially given that I sometimes have to drive as part of my job. So long as one is in the city of Portland or its immediate suburbs, one will find these friendly lights that allow someone to turn left freely across an intersection with the caution light flashing so long as one is free to do so, instead of allowing left-hand turns only at the beginning or end of a light cycle. Of course, the trick is that when one goes beyond the suburbs to the exurbs, these lights are no longer used and one has to become accustomed to waiting a long time at an intersection for the next cycle of lights, which can be a bit irritating for those of us who dislike wasting time.
A major point of interest in the spread of the flashing yellow left-turn light is the fact that it prevents a phenomenon known as the yellow trap, where a car enters an intersection and is trapped without being able to turn safely or know whether incoming traffic has a red light or not . The permissive yellow light, which is one of the names it is called, does not change the behavior of those who are driving straight through an intersection, but it does provide knowledge to drivers who are seeking to turn left–such as the fact that they must yield to incoming traffic, but that they may continue to turn left even if those drivers to their right have to stop at a given intersection under special circumstances. This particular phenomenon started in Oregon, and has since spread to a few other states (including Texas and North Carolina). However, despite the fact that they only started in 2009, their relatively rapid spread (by the slow standard of traffic engineering) has been due to the fact that it serves to reduce ambiguity by giving drivers on the road more information, which increases safety, avoids a major problem for motorists in intersections, and also can allow for more nuanced traffic control.
As readers of my blog will know, I’m all about increasing safety, giving more information, as well as nuance. Therefore, it should be no surprise that I am a fan of the flashing yellow left-turn indicator, given that it serves many of the same purposes that I seek to embody in my own conversation and conduct. Though it is a new phenomenon, the support and enthusiasm of those who have become accustomed to it will no doubt help to further its spread as older lights are replaced with more effective ones that allow drivers more information and allow more options for traffic control of intersections. So, let us salute the clever engineers who thought up of the idea of the flashing yellow left-turn light, coming soon to a traffic intersection near you.