When people here are learning how to drive, they put a huge L on the back of the car. Some cars also have a sign saying don't follow too close. In fact, I risked life and limb to get close enough for Betty to get this picture. I think it might mean Learner, but with all the strange things they are doing, it could mean _______. 
As crazy as taxi drivers and others drive, this adds to the fun. Fortunately, they are not allowed after dark.