> Our review guidelines
Unfortunately, cycling on roads is never a risk-free endeavor. You can’t account for what motorists may do next.
What you can do, however, is minimize the risk of road cycling by following your own code of conduct and becoming risk averse.
Few things are more important to your safety than the direction you take on a bike.
When you’re cycling, do you ride a bike with or against traffic?
Most of the time, you probably ride with the flow of traffic, but what happens if you don’t?
The answer isn’t always as simple as it seems.
Do You Ride A Bike With Or Against Traffic?
Most of the time, and in most places across the world, you should ride your bike with the flow of traffic. It’s unsafe to do otherwise and often illegal.
With the above said, there are many places around the world where contra-flow cycling lanes exist. And research suggests these create fewer accidents, not more.
Contra-flow cycling lanes are sometimes designed to ease congestion on busier roads. They provide cyclists with alternative routes.
In France, where I live, there are many contra-flow cycling lanes, which are used as much by e-scooter riders as bike riders.
The passing distance for motorists overtaking cyclists does not apply on contra-flow roads. Thus, they also exist on narrow lanes with barely enough room for motorists and cyclists to pass each other.
Cyclists and motorists who have direct eye contact are less likely to have accidents. That’s the theory. And it’s probably true, provided the motorist notices you in time.
Reasons To Ride With The Traffic Flow
Riding your bike in harmony with the traffic is usually the right thing to do, but why?
One good reason for riding in the same direction as the traffic is that it’s the right thing to do legally. Most places in the world treat a bicycle as a vehicle in this respect. You’re likely to be breaking the law if you ride against the traffic.
Will you be punished for riding against the traffic? The most likely punishment is a fine if you get caught. But the biggest deterrent has to be the risk to your safety.
Better Anticipation & More Time
When you’re riding at a speed more in sync with the vehicles around you, your ability to anticipate events is greater. It’s easier to read traffic that is moving in the same direction as you because you can often see what the drivers see.
If you ever watched videos of the way bike couriers ride through a city, you’d see all sorts of moves that aren’t legal or wise. But one thing these riders are usually good at is anticipation and feeling the traffic rhythm.
You still can’t account for those times when a car overtakes and makes an abrupt 90-degree turn in front of you. That’s one of those moves that always creates danger when you’re riding in the same direction.
Read more: How to safely turn left on a bike
It feels more natural to ride in the same direction as the traffic around you. Are you always completely relaxed? No. Far from it. But you do know that you’re moving in the direction expected by everyone else.
Even when contra-flow cycling lanes are installed, it’s obvious that many motorists are not expecting to meet anyone coming the other way. As a cyclist, you know this, which may add to your anxiety. Confident cyclists are safer.
Road cyclists who ride clipless pedals are less likely to unceremoniously fall off when they’re moving with the traffic. It’s easier to feel the ebb and flow of vehicles around you and unclip in plenty of time when you’re all going the same way.
Because everyone is expecting you to ride in a particular direction, you’re less likely to have cars, car doors, or people appear suddenly in front of you. Emergency braking is not ideal when your feet are attached to a bike.
(Ironically, being “doored” as a cyclist is marginally worse when the car is pointing the same way as you because the door is less likely to yield.)
If you want to ride quickly, ride with the flow of traffic. Ideally, don’t ride in traffic at all, but riding fast against traffic is inherently dangerous. And it’s worse if there are pedestrians around. You need a measured pace if you’re not with the traffic.
Going with the flow is the way to ride quickly. It can even make you go faster if you catch the draft of a large vehicle ahead, though this isn’t something we’d recommend as safe practice. It’s something pros do when the drivers know they are there.
Video: Professional Cyclist Drafting Team Cars To Save Energy And Ride Faster
To some extent, vehicles overtaking you and sometimes moving in front of you will pull you along in their draft, even if you don’t intend it. For the most part, you should be giving yourself as much space as you can for safe, brisk riding.
Safer Nighttime Riding
Riding with the traffic at night means you’re not subjected to bright headlights in your eye line. Taillights are less bright.
Modern car headlamps are more powerful than their halogen ancestors. And LED headlamps tend to have a colder hue that appears brighter still to the human eye.
You also won’t be subjecting motorists to dazzling lights, which could be an issue if you have an overpowered light fitted to your bike.
When you’re riding with the flow of traffic, you can take up more road where required to stay safe and discourage close passes. You can “take the lane”. This is not a possibility when you’re riding against the traffic, whether legally or otherwise.
Bear in mind that many legal contra-flow cycle lanes are not really lanes at all, so you have no “safe space” to ride on as such. Motorists and cyclists are expected to sort it out between them when they meet at a bottleneck.
To ride against the flow of traffic in many instances is to accept close passes and be squeezed to the side of the road. You may be forced to ride close to other hazards like parked cars, potholes, or heavily populated sidewalks.
Road Signs & Traffic Lights
When you ride with the flow of traffic, you should be able to see all road signs and traffic lights. These are not things you’ll always notice if you approach from the “wrong” direction, so you could miss all kinds of hazard signs pertaining to that road.
Why Riding Against Traffic Is a BAD Idea
Laws Of Physics
Any brush with a vehicle can be catastrophic for the cyclist regardless of direction.
However, when you’re hit from behind, your riding speed effectively reduces the speed of impact. A head-on collision has the opposite effect.
Using an online momentum calculator, I determined that my momentum when riding a bike at 17 mph would be about 4% of my momentum when driving my car at 30 mph.
At 17 mph and 30 mph, the net speed in a hypothetical head-on collision with myself is 47 mph, as opposed to 13 mph from the rear.
The differences in momentum mean very little deceleration occurs in a car if it strikes a cyclist. In a head-on collision, it’s the cyclist that suffers a huge transition in kinetic energy. This greatly increases the chances of serious injury or death.
Velocity squared is a key component of kinetic energy. Thus, the difference between a rear and head-on collision is greater than the speeds alone suggest.
A net impact speed of 47 mph (21.01 m/s) equals 441.45 units of velocity (m/s²) versus 33.75 at 13 mph (5.81 m/s). In this example, that’s a 13x increase in kinetic energy transferal between a front and rear collision.
The above increase in kinetic energy transferred from the car to the cyclist in a head-on crash affects likely injury severity for the cyclist. Remember, the motorist is absorbing almost none of the impact, so the danger is mainly on the cyclist’s side.
Read more: Dangers of commuting by bike
You could of course reduce risk to a degree by riding slower against traffic, though you’d still have no control over motorists’ speeds. Even if you’re stationary, a car traveling at 30 to 35 mph poses a significant risk to your life.
People Aren’t Looking Your Way
Another big reason for not riding against the traffic is that neither motorists nor pedestrians are likely to be looking your way. They’ll make maneuvers or step off the sidewalk whilst only looking towards the main flow of traffic.
Motorists are always likely to pull out of a parking spot or a junction without looking in your direction if you’re riding against the traffic. The fact you might be doing it legally doesn’t always make much difference.
If you are struck by a motorist whilst riding the wrong way, your culpability will work against you. You’re likely to be awarded less compensation, if any, under such circumstances.