This is my second log-entry for my Human-Computer Interaction class this summer.
When I first moved to Center City, Philadelphia, one thing that struck me as odd was the use of regular traffic lights as pedestrian signals. Even at the intersection of two one-way streets, there would be traffic signals in all four directions. There are generally not separate pedestrian signals.
Pedestrian signals in Center City, Philadelphia
While you will find separate pedestrian signals at broad intersections, these are the exceptions rather than the rule. (Perhaps other cities do this too, but if so I have not taken notice.)
After living here for years, it very quickly becomes a part of the landscape and no longer seems abnormal. But I took notice again this year on the 4th of July: a big holiday in Philadelphia that draws a lot of tourists. I noticed a fair number of confused pedestrians, but also a couple of drivers who attempted to drive the wrong way down one-way streets.
It is a convention at most intersections in most cities that if one direction has a visible traffic light, traffic is expected to flow in that direction. Drivers from out-of-town, many of whom are not used to one-way streets, see these pedestrian signals and think they indicate the direction of traffic. But really, it’s only foot traffic, on the sidewalk, that flows that direction. Sure, there are other visible signs: one-way signs and cars parked facing only the opposite direction. In the absence of immediate oncoming traffic, though, those signals can really send the wrong signal.
Why did Philadelphia choose to use the usual automobile traffic signals for pedestrian signals? I assume it saves money: not that the signals themselves are necessarily more costly, but that one computer/controller–or perhaps a simpler controller–can manage each intersection. I don’t really know the reason, though. I definitely feel that it is a mistake to break such a common convention. On the other hand, though I have seen confused pedestrians and drivers, I have yet to see an accident caused by this confusion.Rental