Jul 22 2014
A recent piece by Marcos Netto, TNO‘s Southern Hemisphere Correspondent, mentioned an article on cycling safety that he’d written for the Itati corporate blog. (Marcos is a director of Itati, a Brazilian mineral water company.) It’s a good article on an important subject, but unfortunately for North American and British readers, the blog is in Portuguese, and the Google translation leaves much to be desired.
We figured we could do a better job than Google did, and with Marcos’ invaluable assistance, we have. Here’s the result:
I see a lot of cyclists who ride against the flow of traffic — in the States they’re often called “salmon cyclists” — and when I ask them why they do what they do, they often say they feel safer when they can observe cars coming at them. This, they claim, makes it easier for them to avoid collisions. And these are collisions from which the cyclist always comes out second-best.
It’s a common sense argument, I suppose, but like a lot of common sense arguments, it’s wrong. Dead wrong. And to make matters worse, going against the flow is also inefficient. So let’s take a look at the case for going with the flow. To begin with …
Riding With Traffic is Faster. Cyclists who go with the flow slow down, swerve, and stop less often. That means they maintain a higher average speed and arrive at their destinations more quickly. If you’re just riding to ride, this probably wouldn’t matter. But if you’re riding to go somewhere — to a job or an appointment, say — it does.
And that’s not all.
Riding With Traffic is Also Safer. If you go with the flow, you’re part of the traffic, not an obstacle that traffic has to detour around. According to John Forester, a trained engineer whose book Effective Cycling (MIT Press, 1993) became the bible of the Vehicular Cycling movement, cyclists riding with traffic are about five times less likely to be struck by cars than riders who go against the flow. And while some of Forester’s conclusions have been challenged in recent years, this one has stood the test of time. According to Bruce Mackey, Nevada (US) State Education Officer for Bicycle and Pedestrian Safety, 25 percent of accidents involving cyclists in the United States can be attributed to the cyclists’ decision to ride against the flow of traffic.
And why is this? One reason is obvious:
Riding Against Traffic Gives Cyclists and Drivers Less Time to React. Rear-end collisions — collisions attributable to a motor vehicle striking a cyclist from behind — make up less than four percent of total collisions, yet cyclists who ride against the flow of traffic often explain their actions by citing a fear of being hit from behind. But let’s look at the realities. It requires time for both cyclists and motorists to recognize that a collision is imminent and take appropriate action. Wrong-way cycling robs both cyclist and driver of critical seconds. If a cyclist traveling at 12 mph approaches a car head-on when the car is traveling at 36 mph, cyclist and car are closing at a combined speed of 48 mph. This doesn’t give either party much time to react to an impending collision. On the other hand, if the cyclist is moving with traffic, the car closes the gap at only 24 mph — half the closing speed in the previous scenario, when the cyclist was going against the flow. This gives the motorist twice as much time to brake or steer around the cyclist. And those seconds can make all the difference.
The bottom line? Going with the flow improves your chances of getting to your destination in one piece. And you can improve the odds even more by maintaining good situational awareness. This means using a mirror and keeping your ears open.
OK. So far, so good. But suppose the worst happens, and a car hits you? Well, you’re still better off going with the flow, because, all other things being equal, …
Head-On Collisions Are Worse Than Being Rear-Ended. This is physics, pure and simple, and it follows from the analysis in the previous paragraph. Closing speed determines the energy of collision. And that energy increases as the square of velocity. So in the unhappy event of a collision between a car and a cyclist, anything that reduces the closing speed at impact is good. In our earlier example, the wrong-way cyclist approached the car at 48 mph, whereas the car closed with the cyclist who elected to go with the flow at only 24 mph. If a collision had been inevitable, the wrong-way cyclist would have been subject to much higher forces than his go-with-the-flow counterpart. This is not good news for the wrong-way guy.
Nor is he (or she) any better off when turning.
Riding With Traffic Lessens Risks in Turns. One of the most common causes of collisions is the motorist who makes an abrupt crossing turn in front of a cyclist, and here, too, the wrong-way cyclist has less time to react. Of course, it’s better if the motorist sees the cyclist, slows, and then turns behind her. And this is more likely if the cyclist is in the lane, going with the flow of traffic. (Forester recommends “taking the lane” as a matter of routine, arguing that this improves the chances that the cyclist will be seen. It’s not bad advice, though the strategy isn’t foolproof. If a driver’s eyes are on his smartphone, for instance, it doesn’t matter where the cyclist is. She’ll be invisible.)
“Invisible” cyclists are also at risk in intersections, since …
Motorists Can’t See Cyclists Who Aren’t Where They’re Looking. Now this is common sense. And it’s important, because a high proportion of car-bicycle collisions happen at intersections. When motorists approach an intersection they scan the road in the direction of oncoming traffic. They don’t expect cars to travel the wrong way in a lane, so they don’t look there. Take a freeway entrance ramp, for instance: When a Brazilian or US motorist merges with the high-speed traffic, she looks to the left for a gap in the line of oncoming cars, not to the right. Much the same thing happens at intersections. A driver preparing to enter an intersection looks left to see if the near lane is clear. Then she looks right, to see what’s coming in the far lane. She doesn’t expect to see cars going the wrong way in either lane, so she doesn’t look for them. And that means she won’t spot a wrong-way cyclist, either.
Of course, there are all sorts of intersections, and these include …
Driveways and the Entrances to (and Exits From) Parking Lots and Garages. Here, too, motorists look only in the direction they expect oncoming traffic. The wrong-way cyclist is invisible, and any last-minute attempt on her part to take refuge on the sidewalk is likely to be frustrated by parked cars.
And while we’re on the subject of parked cars, …
Drivers Don’t Look for Wrong-Way Cyclists When They Leave Their Cars, Either. Many motorists don’t bother looking in the side mirror before they open their car doors, but almost no motorist checks for wrong-way cyclists who might be coming toward him. The result is likely to be painful for both parties, but the cyclist will probably get the worst of it.
Speaking of getting the worst of it… So far the cyclist has born the brunt of any collision, but when a cyclist collides with a pedestrian, both parties are likely to be injured, and …
Pedestrians Don’t Expect Wrong-Way Cyclists. Walkers, like motorists, look in the direction from which they expect danger to come. They aren’t likely to spot a wrong-way cyclist — until it’s too late, that is.
This is a lot to take in, I know. But it can be summarized in one sentence: Cyclists who want to minimize their risk of collision are well advised to …
Behave as if They Belong on the Road. While there are no guarantees, a cyclist’s chances of getting through the day without mishap can’t help but be improved by being seen — and by being seen to behave in a predictable way. Such “good manners” have another benefit, too. For all the reasons outlined above, the wrong-way cyclist’s day is a series of narrowly averted disasters. His journey from Point A to Point B is punctuated by a succession of panic stops and sudden swerves. These slow him down. And that doesn’t help him get where he’s going, on time and unruffled. When all is said and done, therefore, going against the flow is tiring, difficult, and dangerous. Just ask a salmon.
Of course, salmon don’t have any choice in the matter. But you do. You’re smarter than a fish, aren’t you? Sure you are! So make it a habit to go with the flow.
- “Pedalar na contramão: muito mais perigoso!”
Marcos’ original article (in Portuguese).
- “Wouldn’t It be Wonderful? A Cleaner, Healthier, Safer World”
- “Bicycling Street Smarts: Where to Ride on the Road”
- “How to Not Get Hit by Cars”
- “Bike School: Cycling in Traffic” (In Portuguese)
- “Street Cycling” (In Portuguese)
- “Traffic Safety Solutions in the Works”
From the June 4, 2004, Las Vegas Sun.