WASHINGTON -- On my daily commute, I bike through a Frogger-worthy array of door-opening drivers, bike-lane-blocking taxis, and heedless jaywalkers. And then there are the other cyclists, my allies in obstacle avoidance. In the seconds after dodging the chrome-plated kiss of some cellphone yakker's Toyota 4Runner, it's soothing to glide over to a fellow rider and whisper, "Did you see that (fool)?!?" At least it would be soothing, if my comrade-on-wheels could hear me. Most days, I ride past more than one biker who's cruising around with her ears plugged up. Cyclists, please hear me out: If you're wearing headphones, you're as much of an idiot as that guy in the 4Runner.
There are very few occasions these days when portable electronic devices are considered off limits. (At last check, we were down to select funerals, art-house movies and the first and last 10 minutes of air travel.) In an age when earbuds are removed only while bathing -- and don't worry, we have the technology to solve this problem -- the bicycle lies in a gray zone of quasi-connectedness.
As opposed to texting while driving, listening to music while you pedal isn't so transparently stupid that it invites universal condemnation. A sensible-seeming, spandex-swaddled fellow might tell you that hearing isn't all that important when you're on a bike -- and besides, a headphoned rider can hear a lot better than a dude blasting his car stereo. And when it comes to legislation, there's no nationwide consensus. Bike riders in Florida and Rhode Island are prohibited by law from wearing headphones. In several other states -- including New York, California, and Virginia -- you can listen to whatever you like so long as you keep one ear free. And in Massachusetts, North Carolina, Illinois, Washington, D.C., and elsewhere, there are no restrictions on listening to podcasts on your 10-speed.
Whether or not it's legal where you live, there is no defensible reason to listen to Stealer's Wheel on wheels. I can't cite any convincing research on headphones and bike safety -- as far as I can tell, there isn't any. This is also not a bogus trend story: You can find plenty of horrible news items about cyclists in headphones getting maimed or killed by trains and buses, but I can't say for certain that such incidents are on the rise. Plus, the presence of earbuds at the scene of an accident does not prove causation: A headphone-wearing cyclist can get sideswiped by a truck while riding cautiously in a bike lane.
What we're left with is common sense. When you're riding a bike on a busy city street, you need to be fully aware of your surroundings. There are cars turning in front of you and racing up from behind. There are pedestrians who, seeing no motorized four-wheeled vehicles to their left or right, mosey into the street without regard for the big red hand on the don't-walk sign. There are potholes and speed bumps and double parkers -- and just wait until you get to the next block.
Cyclists mostly rely on their eyes to weave through these obstructions. It's less common for your ears to serve as your primary warning system -- rare is the day that a barking dog notifies me that I'm about to get doored by a Subaru. Indeed, there's no prohibition against deaf people cycling, nor should there be. And unless you're cranking Japanese noise rock at cochlea-eviscerating volume, your music will never occlude all other sounds. You'll still hear car horns and sirens and motorists screaming about all the fixie-riding Commie hipsters in the turning lane.
But even a burbling sonata can prevent you from picking up on subtler cues, and cyclists need all the cues they can get. Cars have air bags and crumple zones. Bikes do not. Cars have side and rearview mirrors. Most bikes don't. Cyclists must crane their necks and look backward constantly. If your head and your front reflector aren't pointing in the same direction, then auditory signals are essential to staying upright.
In the interest of science, I strapped on my over-ear headphones before a recent morning ride to the office. Listening to music at medium volume didn't hamper my ability to navigate the road in front of me. I did lose all sense of the world behind me. The distant hum of a car closing in from a half-block away, the rusty chain of a bike inching up on my back wheel -- these sorts of aural warnings couldn't overpower the thrum of mid-'90s guitar-based rock. I also became disconnected from my own ride. Rather than propelling a machine with creaky moving parts, I was sitting atop a soundless chariot. It was a sensation I'd never had before: feeling like a passenger in a one-man vehicle.
The music did make the ride go faster, though. It encouraged my mind to wander, giving me something to think about aside from the store fronts and sidewalks I've zoomed past every weekday for the past two years. Was I distracted enough to put other people at risk? I doubt it, but I don't think that should be my decision to make. "Like motorists who insist that they can safely text and drive," wrote Bicycling.com's Neil Bezdek last December, "perhaps cyclists should skip the headphones simply because it's unfair to take unnecessary risks in other people's road space, regardless of personal risk tolerance." Riding a bike during rush hour is perilous. The best way to mitigate that danger is to avoid as many distractions as possible. And music is a highly avoidable distraction.
Erring on the side of alert silence is especially important for the majority of urban cyclists who, like me, make a habit of coasting through stop signs. Though it might appear hypocritical for an avowed violator of traffic laws to give a lecture about safety and risk tolerance on the public way, the truth is that the rules of the road were designed for cars, not bikes. Cycling is about maintaining momentum. It's inefficient, and I'd argue more dangerous, to come to a full stop, put your foot down, and restart at every intersection. Treating stop signs as yield signs -- looking both ways, and coasting through if nobody's coming from either direction -- is both safe and sensible. That's the law in Idaho, and it "has resulted in no discernible increase in injuries or fatalities to bicyclists," according to the state's Transportation Department. (And come on, let's be real: Cars roll through stop signs, too.)
But even if this is a rational move, engaging in this behavior is a decision you're imposing on others. The serial moving violator bears a responsibility to himself and others not to screw up -- to keep his eyes and ears open and his brain locked in. That doesn't leave much leeway to ponder that awesome point that Robert Krulwich just made.
For those who can't survive a tuneless commute, there are companies that make headphones designed for cycling -- devices that use "bone conduction" or mix sound into a single ear to allow "the wearer to maintain alertness in any environment." But these technological workarounds drown out the bigger-picture questions here: Is it really so horrible to spend a small part of your day focused on a single task? Is bobbing through a sea of two-ton SUVs while perched atop a narrow, unenclosed frame on wheels so dreadfully boring that you're desperate for something else to do? If so, then find the nearest bike path and rock out with your sprockets out. If you want to stay on the streets, turn down the sound and put your earbuds in your messenger bag.
• Levin is Slate's executive editor.