I wear a blue tooth head phone in one ear and I do listen to audio, internet radio, and for incoming texts and calls. Bluetooth delivers decent quality audio and I can still hear traffic coming up around me and at least one ear drum stays warmer on cold days. And no more wires like in the old days. And the additional risk, if any, is minimal. I'm not racing at 22mph, but casually commuting at 15 - 17mph on lesser traveled thoroughfares. I would say to the folks who must contend in city traffic, that yes, wearing headphones might be a distraction, but really, it always has been and continues to be an individual ability.
Some folks can process dynamic images and sound and continue to keep that flow in their minds and they might even process in 3D or better (they understand momentum and position). Some can take only static snapshots with no sense of vectors of any objects. Some can only process what they see at the moment and they're too deaf from listening to loud music all their lives. Similarly, some folks can only process all I/O voice and visual through a limited cortex and serially, so they're slow. Others have co-processing in their brains that take in 100x more information and glean it for what's relevant and a very short time.
So if you're able to do it, and not get distracted, more power to you. But know yourself and test yourself. If you're marginal on the reflex and peripheral sensory detection side of the population, then perhaps no headphones are recommended. But if you're the anger-management kind of person internally grumbling because the first 6 cars are taking 8 seconds to accelerate off the line at a red just turned green, two cars on the right have invalid license/registration, the car behind on the passenger sign is still signalling and left the blinkers on, and the car behind is tailgating and producing way too much smog so you don't want him to get ahead, plus he picks his nose really deep so you don't ever want to shake his hand, and you actually are processing this in a 100 millisecond glimpse, then yeah, probably you could use headphones which would make you more relaxed, unless they zone you out and make you sleepy.
But know yourself first.