I know the group I ride with does NOT allow headphones because we have a rotating paceline and ride in major traffic. Personally, when Im on the path alone in the early morning, its ok to me as long as the volume isnt too loud to where I couldnt here anything and Im riding it safe. But, when I get on the road, the headphones come off and get put away, so I can use all of my senses to keep from getting hit and help me get where I need to go. Also, it's illegal where Im at to wear headphones while riding a bicycle on the road, so there's extra incentive not to wear them while on the road.