A seemingly small difference in vehicle speed can mean life or death for a pedestrian or cyclist, and not just because it heightens the force of impact in a collision. It's not just because physics. It's also because psychology.
By Michelle Martin
Published August 04, 2016
Perhaps I need to disclose an interest before writing about lower speed limits, since streets designed to eliminate traffic accidents involving pedestrians would definitely make my day job easier.
Teaching people with developmental disabilities how to cross an intersection safely would be much more straightforward if pedestrian movement was the priority always and everywhere.
But I also have an interest for my own sake. After all, on the days when I walk or take the bus to work, I count on arriving alive. I have an interest for the sake of my children, grown and not, who walk, bike and take public transit every day.
Actually, everyone I know and love has to walk and cross streets sometimes, even if they usually travel by car. And I don't think it's too much of a stretch to say that we all have loved ones who have to walk somewhere, sometimes. So let's all disclose our interest together.
Speed kills: we know this. We know that the faster a car is travelling when it hits you, the more likely you are to be killed - because, as we learned in high school, Force = Mass x Acceleration.
We know that a big part of the campaign to reduce pedestrian fatalities has been lowering speed limits on city streets. We also know that a posted limit of 50 km/h often translates, in practice, to traffic flowing at 60 km/h or even more.
The unconvinced among us retort that they are good drivers, so they don't hit people and they should be allowed to drive at 50 km/h and faster if they feel they need to. And if a pedestrian makes an error, well, that's the pedestrian's fault.
There's clearly a power imbalance here: in a serious accident where a pedestrian is "at fault", one person gets a cracked windshield and maybe a "failure to yield" charge, the other ends up dead or seriously injured.
Obviously the onus is on the driver to take all the care necessary to avoid hitting pedestrians or cyclists, whether or not those pedestrians or cyclists are in error.
"With great power comes great responsibility" - this approach to justice that has been around for centuries (no, Marvel Comics did not invent it), reaching at least as far back as the New Testament ("From everyone to whom much has been given, much will be required"), maybe farther, I don't know. Philosophy wasn't my course of study.
I'll stick to psychology for now. Consider what the human brain is capable of doing at any given moment. Think about how much you can attend to at one time. Think about the complicated endeavour that driving is.
When we drive, we have to attend to our own speed and use our car's signals correctly (did you turn off that left indicator?). We have to attend to road signs and traffic lights. We have to judge the speed and distance of other vehicles, including bicycles. We may be navigating an unfamiliar neighbourhood. We have to listen for emergency vehicle sirens. And we have to watch for pedestrians.
We have to take all of these pieces of information in as they occur, and make split-second decisions about how we will respond.
Even the most practiced drivers among us do not do all these things simultaneously. Multitasking was debunked long ago. We may think we are doing several things at once, but we are actually switching very quickly between individual tasks. Adding an unnecessary, immediately unrelated task while we drive can tip the balance dangerously.
Our increased understanding of human cognitive abilities, informed, unfortunately, by carnage on the road, has led to distracted driving laws with large fines attached to them, and rightly so.
What do speed limits have to do with this? Consider that when we drive, we have to pay attention to road signs, traffic signals, other vehicles, and pedestrians as we approach them. The faster we travel, the less time we have to make a decision and act on it.
And when we increase our speed, our useful visual field decreases. Even if objects or people are in our actual visual field, on either side of it for a split second, we just aren't aware of them. As our speed increases, we experience a kind of tunnel vision.
Driver's peripheral vision at 16-25 km/h (10-15 mph) (Image Credit: National Association of City Transportation Officials, New York, NY, accessed August 3, 2016)
Driver's peripheral vision at approximately 16-25 km/h (10-15 mph). Notice how a driver can take in who is on the sidewalk at this speed and, to some extent, at the speed illustrated below.
If you are driving close to this speed and notice a child on the sidewalk bouncing a ball, or riding a tricycle, you've got time to cover your brake and be on guard, just in case.
Driver's peripheral vision at 32-40 km/h (20-25 mph) (Image Credit: National Association of City Transportation Officials, New York, NY, accessed August 3, 2016)
Driver's peripheral vision at approximately 32-40 km/h (20-25 mph). A Swedish initiative on road traffic safety called Vision Zero, which sets a standard of zero traffic fatalies that has quickly spread around the world, including to Hamilton City Council [PDF], recommends a speed limit of 30 km/h.
A comparison of the first and second pictures shows why: it would increase the chances of a driver noticing if a pedestrian has just stepped off the curb.
A large number of Hamilton streets (250 to date) have had the posted limit reduced to 40 km/h. One Hamilton neighbourhood has had their posted speed limit reduced to 30 km/h. We aren't the only city to do this.
Driver's peripheral vision at 48-56 km/h (30-35 mph) (Image Credit: National Association of City Transportation Officials, New York, NY, accessed August 3, 2016)
Driver's peripheral vision at approximately 48-56 km/h (30-35 mph). In Ontario, the statutory speed limit, or the assumed limit in the absence of any signs, is 50 km/h in urban areas. Many municipalities (including Hamilton) are lobbying the provincial government to reduce it. Our province's chief coroner has recommended reducing it to 40 km/h.
Driver's peripheral vision at 64+ km/h (40+ mph) (Image Credit: National Association of City Transportation Officials, New York, NY, accessed August 3, 2016)
Driver's peripheral vision at approximately 64+ km/h (40+ mph). In Ontario, the statutory speed limit is 80 km/h in rural areas. This picture explains why Highway 5 can be a death trap for cyclists who have no other means of transportation.
It may also prompt you (like it prompted me) to ask yourself how often you've found yourself inadvertently driving 60 km/h on Hamilton streets, like King, Main, Mohawk, Stonechurch or Rymal, and to think about the risk you may have incurred.
Yes, a seemingly small difference in vehicle speed can mean life or death for a pedestrian or cyclist, and not just because it heightens the force of impact in a collision. It's not just because physics. It's also because psychology.
And if you weren't aware of the effect of speed on your peripheral vision before, you are now. Knowledge is power, and with power comes responsibility. Slow down, especially when there may be pedestrians and cyclists around. Because philosophy.
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