I’ve never been terribly successful with the cabs in my visits to NYC. For some reason they don’t like to stop for me, and I was never quite sure of the rules.

Now, according to the New York Times, the NYC Taxi and Limousine Commission is looking to redesign the Off Duty signs. After reading about this, looking back on my experiences, it makes a little more sense.


If you’re not from New York and not used to the system, how do you tell that the cab is available? If the medallion number is lit, the cab is available. If it’s not lit, the cab is not available. But then the medallion number if flanked by an Off Duty light that the cab driver can illuminate if the cab is off duty. Which apparently means they’re sort of available but they don’t have to accept passengers.

But what does the medallion number mean? And why does the number being lit mean available when lighting Off Duty means probably not available?

Sure, it doesn’t take too much to learn, but figuring out if cab is available shouldn’t require an instruction manual. How about a sign that lights green and says Available when the cab is available and switches to a red Not Available when the cab is not available? It puts the knowledge in the world by using a simple description and enables redundancy gain by using both color and words. (It also has the benefit of working for people who are color blind, unlike using only a light.)

I worked on the design of one of the contenders for the eTaxi system a few years back. It was fascinating to me how highly politicized every design decision was. Taxi drivers and owners ultimately don’t have a say, but they do have a union and can make trouble. And these design decisions cost the cab drivers money which they can’t easily recoup as the TLC sets their rates. In the end, decisions are made by the TLC. It will be interesting to see if they can push this change through.