http://www.crunchgear.com/2010/08/06/rash-of-traffic-accidents-blamed-on-ipod-oblivion/

The Apple iPod is being blamed for more than 17 accidents per day in the UK.  They have coined the term “iPod Oblivion” because runners, walkers, bicyclists, etc. are “so into” their music that they ignoring or unable to hear the dangers of traffic around them.  If you run, walk, or ride with music while on the road, keep the level down so that you can hear the sound of approaching vehicles.  Remember to run or walk facing traffic, ride your bike with traffic, and go out of the way to make yourself highly visible, especially at dawn and dusk.  Be defensive – the car always wins.