Thursday, September 29, 2011

In defense of "dumb" traffic lights

A pedestrian "beg" button (source)
After spending some time in the Bay Area, one thing I noticed was the ubiquity of "smart" traffic signals. These are equipped with sensors and gadgetry to detect cars, and sometimes bikes, and make decisions based on that. In contrast, most intersections I can recall in East Coast cities are not augmented in this fashion. Smart signals have the advantage of dynamically adjusting phases according to traffic. They also take into account pedestrian button boxes.

I also noticed that the city of San Francisco eschews the smart signals in favor of "dumb" signals which merely operate on a timer. Most intersections do not even require pedestrian buttons, the Walk phase is always included.

Almost needless to say, San Francisco is a much friendlier walking place than anywhere else in the Bay Area. There are many reasons for this, including density, public transit accessibility, and well-connected streets. I think that the "dumb" street lights are also part of this advantage. Predictable, short phase signals allow pedestrians to cross safely without waiting for interminable periods of time. They also provide the same advantage for drivers. While you do lose the advantages of "smart" signals for automobile traffic, those same "smart" signals provide no help to pedestrians.

Being forced to press a button in order to beg the system for a Walk signal is tantamount to relegating pedestrians to second-class status. When walking, you may have to stop at every single intersection, press a button and wait. That is assuming the buttons work, which based on my experience, is often not the case. Then while waiting you find yourself trying to guess whether or not the button is working, or whether you have simply not waited long enough. One time in San Jose, we waited for two whole cycles of the light phases before giving up on the button and crossing 8 lanes of traffic anyway. Luckily it was very quiet that evening.

In Boston, there are not many "smart" signals but they do use buttons ubiquitously. However, the traffic signals and pedestrian "beg" buttons are so unreliable and so often out of order that most people don't even look at them and cross along with the parallel car phase. That is, if they don't just jay-walk. There is a great deal of cynicism about the traffic signals, and a great deal of pride in Boston's status as a walking city. It has even been rated the safest walking city in the country. I just wish that City Hall would get its act together and realize that pedestrian "beg" buttons do not belong in any real city.

Drivers should also appreciate the fact that they do not have to "find the sensor" in the road in order to get a green light, nor that they miss phases because "they weren't there in time."  I know that people will speed up as they arrive in front of "smart" red lights because they want to activate the sensor before the next phase begins. That is simply not an issue with the old-fashioned system. Sometimes we out-smart ourselves.

1 comment:

  1. Thank you. I look forward to the day when pedestrian actuation buttons are banned and pedestrians are always given a walk signal.

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