For the first time since moving to Beacon Hill, I noticed a change in the length of a walk signal. The intersection of Beacon and Charles Streets- right where Beacon Hill meets the Public Garden and the Boston Common- recently extended the length of its crosswalk signal from sixteen seconds to twenty-two seconds.
It was a long time coming. A lot of pedestrians struggled to make the crossing in time. Often, the light would turn to green while little old ladies, moms with strollers, or unemployed bloggers were still in the crosswalk.
I like the move because the solution directly addresses the problem. There was simply not enough time to cross. So, time was added for crossing. It seems like an obvious approach- identify a problem and address it directly- but I often see indirect measures applied instead.
One notable example is at (a different) Beacon Street in Cambridge. The intersection of Beacon and Kirkland recently saw the length of the yellow light extended from the 'usual' time (two or three seconds) to somewhere around five or six seconds. (1)
The reasoning for the change is obvious, perhaps, but I wonder if experienced drivers will soon start running the yellow light as they become accustomed to its extended length. It seems that, though initially the intersection is 'safer', eventually more cars will accelerate through the yellow than they did prior to the change. After some time, my guess is that traffic will return to pre-adjustment conditions as drivers learn how this one yellow light is an exception to the rest. (2)
To me, the solution for problem intersections seems simple enough- just hold the red light. No one will run a red light even if it is unusually long. But holding the red for an extra beat or two creates wiggle room in case anyone makes an error. And unlike with running a yellow light, running a red light is a much easier law to enforce.
Bike friendly areas tend to extend the red instead of extending the yellow. Other parts of Cambridge already do this. I am not sure why Beacon and Kirkland became an exception (though I do suspect there is a very explainable reason that I am unaware of).
A soccer referee knows that decisions about red and yellow are not made sequentially, not simultaneously. If red makes sense, its red. Only after ruling out red is yellow considered. Stoplight policies at problem intersections would do well to universally adopt such an approach.
Footnotes / imagined complaints
1. I mean, only if you are really bored, though...
It's not a bad place to hang out and watch for a bit. It's a laugh to see a car stop completely at a yellow light for over two full seconds.
2. True On Average: a boutique applied economics blog...
Granted, this idea of 'pre-adjustment levels' is just my economics degree talking. The idea that users adjust to changes over a period of time and everything returns to 'just the way it was' is a standard feature of many undergraduate economics classes.
In real life, things never settle long enough to return to the starting point. It's like saying an inflated beach ball in a crowded swimming pool will eventually float motionless on the surface- though that might have been the starting condition when the pool opened, the projected return to that condition is challenged by the reality of all the little kids kicking and thrashing and screaming about in the pool. Once those factors are considered, it is probably more likely that the ball will be deflated, kicked out of the water, or taken home by a swimmer.
