What Traffic Engineers Don’t Want You To Know

The following is an excerpt from Killed by a Traffic Engineer: Shattering the Delusion That Science Underlies Our Transportation System by Wes Marshall.

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Killed by a Traffic Engineer: Shattering the Delusion That Science Underlies Our Transportation System

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Let me tell you a story about the time I ended up in a Cabo San Lucas emergency room where a doctor slowly and methodically dug around each of more than a hundred sea urchin needles and pulled them out of my feet like vertical splinters.

The localized anesthesia shots hurt just as much as his digging, so I figured I might as well skip the shots. My approach to pain management was staring intently at some Spanish version of the Hippocratic oath hanging in a rusty frame on the wall. I tried to translate it in my head. I thought about the life of Hippocrates. I felt happy to live in a time where we must know a heck of a lot more about medicine than he did.

In the years since, I’ve learned that it’s been a long and painful journey for modern medicine to get to this point.

Don’t get me wrong; we need to give doctors their due. Anesthesia. Germ theory. X-rays. Antibiotics. Vaccines. DNA. Organ transplants. Chemotherapy. Magnetic imaging. The human genome. The list of medical advances that we now consider commonplace is loooong. Everyday medical treatments of today would have been considered a medical miracle not that long ago. Before the discovery of insulin in 1921, diabetes was a death sentence.

But for at least the first 1,000 years after Hippocrates, it wouldn’t be hard to make a case that doctors killed more people than they saved. On his Against the Rules podcast, author Michael Lewis says, “For roughly 5,000 years, people called themselves doctors and pretended to know all sorts of things that they didn’t know and were as likely to kill you as to cure you. These doctors existed because sick people desperately wanted to believe them.”

Doctors in the early 1900s treated coughs and sore throats—in kids—with heroin.

During this time, doctors used X-rays to remove unwanted hair … and give people cancer.

Through the 1940s, doctors used the radioactive substance radium in an attempt to cure anything from asthma to blindness.

Doctors continued to recommend smoking to relieve throat irritation well past the US surgeon general’s report on smoking and health in 1964.

As late as 1967, Dr. Walter Freeman performed lobotomies (in his Lobotomobile) in an attempt to cure mental illness, hyperactivity in kids, and minor neck pain. Freeman’s 14 percent fatality rate on more than 3,500 lobotomies doesn’t do justice to those left in a permanent vegetative state.

Want a transportation-related example? Doctors treated everything with bed rest and scoffed at the benefits of exercise—unless “taken in Olympian doses”—until the mid-1970s, when Laurence Morehouse and Leonard Gross’s book, Total Fitness in 30 Minutes a Week, redefined “exercise” as “increased physical activity” where even walking counts. It took until 1986 for the research to catch up and show that increased physical activity helps with mortality.

Even now, many doctors won’t advise walking or biking for transportation as a health intervention. Why? Because they assume that the road safety and air pollution risks outweigh the physical activity benefits. That isn’t the case everywhere. But given that much of the transportation system was built by civil engineers, these doctors may have a point.

This is something we need to fix.

Civil engineers have also been around for about 5,000 years. Like doctors, they’ve learned a lot in this time.

When people think about civil engineering, most think about structural engineering and public works projects such as roads, bridges, and dams. But civil engineering is a huge umbrella that encompasses most anything related to the design, construction, and maintenance of the built or natural environment. Civil engineers developed the first sewer systems, and modern sanitation alone apparently added 20 years of life expectancy.

Traffic engineering falls under the umbrella of civil engineering, but traffic engineering has been around for less than 100 years.

A 1965 British report explains the origin story of traffic engineers: “In order to deal with traffic problems in a satisfactory way, it has been necessary to build up a scientific discipline” and, as a result, “a relatively new branch of engineering has therefore been evolved, that of traffic engineering.” I also found a 1959 paper published in Traffic Quarterly, the preeminent traffic-engineering journal at the time, stating that “only the last decade has witnessed the adulthood of traffic engineering” and that “there are few things today that are more important to the welfare of the modern community than good traffic engineering. It is right up there with medicine and education as a factor in the everyday life of every citizen.”

What do we mean by traffic engineering? The British report simply describes it as “that part of engineering which deals with the traffic planning and design of roads, of frontage development and of parking facilities and with the control of traffic to provide safe, convenient and economic movement of vehicles and pedestrians.”

Safe is the key word there, but like doctors did for a thousand-plus years, traffic engineers spent the last hundred years killing as many people as they’ve saved.

At first, traffic engineers tried to rationalize road deaths, akin to doctors in an experimental field:

“It’s a new discipline,” they’d say.

“We’re on a learning curve.”

But errors by engineers suggest incompetence—even when due to the newness of the science—and engineers don’t want to portray anything other than extreme competence. So, it wasn’t long before traffic engineers presented a nascent scientific field as if it was a finished product.

While the early traffic engineers knew what they didn’t know, subsequent generations of traffic engineers started to believe that they knew more than they did. These traffic engineers then built out the transportation system without ever taking a good, hard look at the science (or lack thereof) behind it all. It’s time to take that good, hard look.

In this book, I’ll show how traffic engineers designed and built a system that incites bad behaviors and invites crashes. The bad behaviors let traffic engineers off the hook, but most deaths and injuries are the predictable, systemic outcomes that traffic engineers inadvertently caused—thus, the title of this book—but that can be fixed.

Just knowing this fact isn’t enough to fix the problem. Traffic engineers hold too much power, as well as the superpower to shut down most arguments. They do so by saying they are following the methods and standards. So if you want to win an argument with a traffic engineer, you need some ammunition. This book provides that by looking at what traffic engineers do wrong today and exposing the pseudoscience that led traffic engineering to create these methods and standards in the first place.

I felt the need to write this book when I realized that we aren’t going to come close to fixing our road safety problems based on what I was taught in engineering school. I began digging into all the systemic things that traffic engineers do wrong. The more I considered the problems we face, the more I realized I needed to figure out why traffic engineers do what they do.

Traffic engineers don’t want you to peek behind this curtain, because most traffic engineers have no idea what’s behind it. But if we want to fix the carnage on our streets, we need to shine a spotlight on how little there is behind the why question. Following the science means first shattering the pseudoscience. Only then can we start making the world a safer place on a larger scale.

The sad reality is that we need a dramatic transformation of transportation, and we need the right kind of mind-set to make it happen. This goes for traffic engineers in particular because they are still the ones in charge of our streets. They won’t change what they do without first changing how they think. If your friendly, neighborhood traffic engineer reads this book, great. If not, this book will teach you how to effectively argue with your friendly, neighborhood traffic engineer.

When you finish reading this book, you’re going to look at your city and streets much differently. Things that never bothered you before are going to drive you crazy.

You don’t need to be a traffic engineer or transportation planner—or any kind of expert—to read this book or join the cause. That is one of the great things about the transportation discipline. Everyone has opinions (lots of them), and (almost) anyone can speak intelligently on their own experiences.

So if you want to learn the truth about traffic engineering and road safety,
If you want to fix our streets and communities,
If you want to make how we get around safer,
If you want to help start us on a path to saving millions of lives,
I’m happy to have you come down this rabbit hole with me.
If not, stop reading now and drive to work tomorrow.

From Killed by a Traffic Engineer by Wes Marshall. Copyright © 2024 Wesley Marshall. Reproduced by permission of Island Press, Washington, D.C.