I guess it makes sense when you think about all of the people who have to commute to work. In the cities with heavy population numbers, messing around with a device (like your cell phone) is sure to get you in trouble. I'm remembering when I visited San Diego and made the drive up to LA. It took hours because of all the traffic. Some people do commutes like that every day. It makes sense that they would listen to a lot of radio on a daily basis. Then they have even less time at home to watch TV and all that.