Why, Airports? Why?

Whoa! I leave for a while and they change everything. We'll see how well this goes...

I'm probably the only one to wonder about things like this, but a while ago I was taking the train from the economy parking lot to O'Hare Airport and noticed that all of the driverless cars on the tram have windshield wipers. Why'd they do that?

From there, I flew on to Dallas, where it was also raining. And lo and behold, Dallas also puts windshield wipers on their driverless airport tram and they do it even more strangely - only the right side of the tri-windows has a wiper. Weird.