It all really depend, where you live - or better: where you listen to the radio*.
You may check the following websites, if you can receive digital radio ... and get some answers to your questions as well:
http://www.bbc.co.uk/digitalradio/
http://www.digitalradionow.com/home.php
*I live here in Germany in a region, where officially digital radio is only difficult to receive. However, I've got digital radio in the car (besides analogue radio) and can receive nearly everywhere all the stations, which broadcast in our state (and when I'm closer to the state borders, even more from their channels). [I must admit, I get 34 FM-stations here in rural Westphalia via my excellent car radio, but only 7 digital ones until now.]