Civil engineer crashes status quo: Lack of research, flawed assumptions fuel roadside carnage

Wes Marshall, a professor of civil engineering at University of Colorado at Denver, says the science of traffic safety is plagued by flawed research and untested theories that don't get at the heart of the problem — inadequate infrastructure to protect people. (Photo by Tim Carpenter/Kansas Reflector)

LAWRENCE — Civil engineer Wes Marshall says government transportation agencies make life-or-death decisions based on data that clouds thinking on how roadway infrastructure ought to be redesigned to better protect pedestrians and bicyclists.

Marshall, a professor at University of Colorado at Denver, said the number of U.S. traffic fatalities since 1899 was approaching 4 million, but those deaths were generally accepted as part of the cost of a modern transportation network anchored to movement of vehicles. He told participants Wednesday in the Walk Bike Roll Kansas summit hosted by the Kansas Department of Transportation that addressing the carnage required a new mindset that placed a premium on examining why dominant methods of engineering killed so many people.

“How do we fix it? We can maybe stop bowing down to the secret art of traffic flow, stop playing whack-a-mole with all our safety problems and try to build better places,” he said.

He said the United States lacked essential research on traffic safety and relied on plausible but unproven assumptions about traffic speed limits, lane widths, roadside zones cleared of obstructions, crosswalks, bicycle lanes and sidewalks. The problems persist, in part, because of a lack of interest among states in gathering the detailed crash-by-crash information that is important to understand the root causes of accidents and what might be done to make the public safer, he said.

“Police are out there to … just figure out who’s at fault for the sake of the insurance companies or for giving citations,” Marshall said. “They’re not taking this data down to help me understand what the infrastructure was like and whether there was a bike lane or protected signal.”

Marshall argued states should do a much better job of tracking injuries and deaths involving pedestrians and cyclists. Most police departments required a minimum $1,000 in damage to take a crash report, he said. In San Diego, he said, there were 250 bicycle crashes in one year that were oddly defined in reports as overturned vehicles.

“Most states, it’s easier to do what we’ve always done,” Marshall said. “So collecting better data that we can begin to trust more, it would be a great start.”

He said traffic fatalities and accidents should be factored in relation to total population rather than miles traveled so the numbers could be routinely viewed in the context of a health risk. Data too often placed responsibility for accidents on human error rather than poorly designed infrastructure, he said.

Marshall wrote the book “Killed by a Traffic Engineer: Shattering the Delusion that Science Underlies Our Transportation System.”

“There are a few DOTs that have banned my book from their library just strictly based on the title,” he said. “I’m an engineer myself, and if you can sort of get past the title, you realize I’m not blaming us. We are doing what we were told. We are doing what we were taught, but what we were taught isn’t quite so. I was told there was science behind all this stuff.”

Marshall intended the book to be of use to engineering professionals as well as community transportation activists. The intent was to evaluate available research, explain transportation jargon and pull the curtain back on the regulatory landscape, he said.

“I’m trying to give everyone ammunition so you can more effectively argue with an engineer. So you can understand what engineering judgment is and how we can use it. Engineers, as we all know, are great at coming to a community meeting, you’ve already decided what we want to do, and we can just shut down things by calling them standards, even though we know they are guidelines,” he said.

It wasn’t enough to design streets, roads and highways to get vehicles from Point A to Point B the fastest way possible, he said.

And, he said, engineers who insisted that making traffic lanes wider would make roads safer at elevated speeds didn’t take into account how motorists frequently took more liberties behind the wheel whenever they considered the road less risky.

“It makes logical sense. It gives people extra room. It should work well, but human beings behave differently on this (wide) road than a narrow one,” he said. “Maximizing the kinetic energy of anything is not what we want in terms of road safety.”

He said infrastructure reform had to supplement educational programs designed to encourage people to behave better on highways, streets and roads.

For example, he said, there was no doubt many cities needed to invest in comprehensive sidewalk networks and in building dedicated lanes for bicycles on streets that featured rigid barriers to protect riders.