I’ve written a number of articles over the years about the dangers of speeding, and of how as humans, we don’t have an instinctive understanding of the crash forces involved. This is Vision Zero talk. It’s about how crashing at high speeds is like falling off a cliff. It’s about how you can’t drive beyond 43 mph on an undivided highway and expect to walk away from a crash. It’s about how speeding is the magic bullet for cutting fatalities in every country in the world. Well, if you haven’t had enough of these articles, here’s another. The information comes from a country that takes road safety much more seriously than we do in the United States (hint: that’s just about every other rich country). Today’s information comes from Sweden, specifically Trafikverket, or the Swedish Transport Administration. They’re kind enough to publish a lot of information directly in English to encourage a wider dispersal of information throughout their population. There I was, reading a brochure late at night titled “Safety in the car – how to protect yourself and your child“, when I came across this bit:

A frontal collision at 90 kilometres an hour is like falling from the tenth floor

Driving too fast can be just as dangerous as falling off a cliff or from a tall building. But we do not perceive the speed as dangerous when we drive a car. We understand the danger of falling from a height, but not how dangerous it is to collide at 90 kilometres an hour.

It’s hard to state things more simply. As noted in the image above, you’d never push that girl off that cliff. You’d never take a jump yourself. But if you get into a crash at 90 kph (55 mph), whether a head-on collision with another vehicle or a frontal collision with a building, a tree, a bridge, or a rock wall, you might as well have. You’re dealing with just as much force in a highway crash as you’d feel if you took a flying leap off a 10-story building, or if you pushed the person you most loved in the world off said building.

The thought is terrible. Unacceptable. It’s something we’d never willingly do to anyone. But that’s not how we see things when we drive. We don’t realize that we’re essentially flying off that cliff; we just happen to be doing so while the ground recedes exactly as quickly as we hurtle toward it.

You might think at this point: Mike, it’s not exactly the same. After all, I’m in a safe car. I’m wearing my seat belt. I’ve got frontal airbags, for goodness’ sake!

The problem is that you still wouldn’t willingly go off a cliff 10 stories high while buckled into a car, would you? Not even if it had a frontal airbag and a good front crash score. Not even if you could be sure of hitting the ground vehicle nose first. And you certainly wouldn’t strap your child into a car seat and roll her off that building, telling yourself she’d be just fine since she were rear-facing or forward-facing or boostered or anything of the sort.

You’re still dealing with tremendous forces. You’re still dealing with a very real risk of death for everyone involved.

We live or die by Vision Zero principles

Vision Zero principles aren’t based on black magic. They’re based on the deaths of tens of thousands of people. The knowledge was gained painfully, with bloodshed and broken hearts. We now know that if, for example, you’re traveling on a roadway with any risk of collision with opposing traffic (i.e., in an undivided highway), traffic cannot be traveling above 43 mph if the goal is for everyone to survive any potential collisions.

A 55 mph collision is 56% more severe than a 43 mph collision. As we’ve discussed elsewhere, the difference in miles per hour isn’t linear; it’s exponential. The formula for kinetic energy involves mass multipled by the square of velocity. In other words, you don’t divide 55 by 43 to see how much more severe the crash is; you divide the square of 55 by the square  of 43 (55*55)/(43*43), which gives you 1.56, or an increase in force of 56%.

To extend the analogy a bit, a crash 100% more severe (in other words, twice as severe) as a 43 mph crash would not be an 86 mph crash, but a 61 mph crash ((43*43*2)^.5).  These crashes, by the way, are almost guaranteed to take the lives of at least 50-75% of people involved in them, based on my analyses of fatal crashes at similar speeds. Keep in mind again that the IIHS tests vehicles for frontal collisions at 40 mph, which they already consider to be a severe collision.

We’re not meant to survive high speed collisions. Not even with the latest vehicle technology. If you’re going to hit something directly, your odds of living drop if that direct hit occurs above 43 mph. And few of us would expect to survive being tossed out of a 10th story window. But those are the risks we take each time we risk a 55 mph crash.

Follow best practices. Do whatever you can to drive safely, choose safe vehicles, and use safe infrastructure.

If you find my information on best practices in car and car seat safety helpful, you can buy my books here or do your shopping through this Amazon link. Canadians can shop here for Canadian purchases.  It costs nothing extra to do so, but when you shop through my links, a small portion of your purchase, regardless of what you buy, will go toward the maintenance of The Car Crash Detective.