Bad signalling

About a month or two back, a new set of traffic lights came up on the way from home to my daughter’s school. It’s among the least effective set of lights I’ve seen.

For starters, the signal cycles are too long to justify the traffic, so if everyone decides to follow the lights, the traffic will only get worse.

Then, on two sides of the signal (the east and west approach roads) the lights aren’t displayed properly. There are lights on the left side of the road just before the signal, but no corresponding lights at a height across the intersection. So if someone is too close to the intersection they can’t see the lights.

Most importantly there has been no attempt at all so far to enforce the lights. There wasn’t even a cop standing there in the days leading up to the installation of the lights. The intersection was never really that crowded to necessitate a signal (ok I have limited data on this). And one day suddenly the lights went up and it was expected that people will follow.

People, for the most part, haven’t, and that’s a good thing considering the signal cycle. The east and west sides (who don’t have lights on the opposite side of the intersection to reinforce the signal) started the jumping first. The north and south sides joined.

I usually approach it from the south side, and the only times I stop at the signal is if someone in front of me has decided to obey the signal and doesn’t let me past. And I suppose that as people hit the signal multiple times they too make an independent judgment that everyone is jumping the signal, and that’s the optimal strategy.

I see this as a case of failed mechanism design. A set of traffic lights is good if and only if everyone has an incentive to follow it, or is made to follow it. For example, once a set of lights go up, having a cop stationed at the intersection for a few weeks means that most regular commuters across the intersection will get used to the lights, and start following it. And once you have a critical mass of commuters following the signal, the rest simply obey.

As things stand now, I’m happy that nobody really follows these lights – for if people did, it would only slow things down!

These lights, by the way, are at the intersection of 26th main and 39th cross roads in Jayanagar 9th Block.

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