Killed by a Traffic Engineer

Why are our roads unsafe, and who is to blame? Transportation expert Wes Marshall joins us to unravel the myths behind traffic engineering, revealing a surprising truth: the science we trust to keep us safe on the road might be more fiction than fact. With his provocative book "Killed by a Traffic Engineer: Shattering the Delusion that Science Underlies Our Transportation System," Wes aims to spark a critical reevaluation within the engineering community and beyond. Our discussion navigates the murky waters of road safety priorities, exposing the stark contrast between common fender benders and high-speed highway fatalities. The episode calls into question the societal and systemic factors that prioritize speed and power over human lives, emphasizing the urgent need to rethink the metrics and methodologies that guide our transportation systems.

Show Notes:

• Further Reading: Walkable City by Jeff Speck, Inclusive Transportation by Veronica Davis, Right of Way by Angie Schmitt, Transit Metropolis by Robert Cervero, The Bicycle City by Dan Piatkowski, Human Transit by Jarrett Walker, When Driving is not an Option by Anna Zivarts
• To help support the show, pick up a copy of the book through our Amazon Affiliates page at https://amzn.to/3YwX6aA or even better, get a copy through your local bookstore!
• To view the show transcripts, click on the episode at https://bookedonplanning.buzzsprout.com/

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Chapters

• 0:12 Challenging Traffic Engineering Standards
• 11:50 Reevaluating Road Safety Priorities
• 16:40 Reevaluating Transportation System Safety
• 26:17 Technology, Cars, and Road Safety
• 30:09 Reevaluating Safety Standards in Transportation
• 33:58 Rethinking Transportation Engineering for Safety
• 43:34 Questioning Traffic Engineering Science

Transcript

Stephanie Rouse: 0:12

you're listening to the booked on planning podcast, a project of the nebraska chapter of the american planning association. In each episode we dive into how cities function by talking with authors on housing, transportation and everything in between. Join us as we get Booked on Planning. Welcome back, Bookworms, to another episode of Booked on Planning. In this episode we talk with author Wes Marshall on his book Killed by a Traffic Engineer, Shattering the Delusion that Science Underlies Our Transportation System. I've had this book on our top reading list for this year's season and was definitely not disappointed.

Jennifer Hiatt: 0:54

Stephanie, I know that this has been your world for a very long time, but I've just recently had to start learning about transportation planning and engineering, and this book was so eye-opening. I definitely feel better equipped to have a good conversation with our transportation engineers.

Stephanie Rouse: 1:08

And West does a good job diving into the history of how traffic manuals developed, their regulations and recommendations, often taken as the holy grail but lacking any real studies or data to back them up. It's a great source for those of us working in communities trying to make them more livable, but getting pushback from the engineers, yeah.

Jennifer Hiatt: 1:26

I have to admit I always thought that you know well, the engineers know what they're doing, so I never really pushed back. So now I have a better toolbox with which to do so in our conversations now. So let's get into our conversation with Wes Marshall on Killed by a Traffic Engineer Shattering the Delusion that science underlies our transportation system.

Stephanie Rouse: 1:46

Well, Wes, thank you for joining us on Booked on Planning to talk about your book Killed by a Traffic Engineer. As a former transportation planner, this is the book that I had been waiting so long to actually be able to read. I'm curious to know how has the engineering community received your book and have you seen a lot of pushback, or are you seeing kind of light bulbs turning on in the transportation field, starting to change the way they do business?

Wes Marshall: 2:10

Well, first of all, thanks for having me. I will say the response from the engineering community has been overwhelmingly positive. But that doesn't mean there hasn't been some pushback. And you know, I think the pushback especially has come just with the title of the book, even though if those folks actually read the book they'll see I'm not. So I've been happy to see some of that pushback because they're still kind of sticking to the guns that I'm just sort of dismantling throughout the book. So I've spoken at some of the major transportation engineering conferences, like IT International, and nobody punched me there. I mean, in fact I think that was the first time I was at a conference where people asked for my autograph after I spoke. So that seems a little bit weird, but it was good.

Stephanie Rouse: 3:08

That's good, because Chuck Maron seemed to have the opposite effect on the transportation community after his book came out. It seems like they started suing and really attacking him instead. So it's good to hear that this book has been received well.

Wes Marshall: 3:23

Yeah, I mean there was one person on the IT forum asking me to resign and stuff, but again, he hadn't even read the book and he was just trying to make sure no one else did too. So I think there are some folks that would rather this book just go away, but that hasn't been happening, so I've been happy about that happy about that.

Jennifer Hiatt: 3:46

Well, I'm pleased to report that in Lincoln we have received word that a few of our transportation engineers, including our deputy director of what is Lincoln Transportation Utilities, have read it and don't seem to want to punch you. So that's good. That's good.

Wes Marshall: 3:57

I have heard that some like state DOTs, like they try to get in their library and they've been told no, it's sort of banned from that. But those same state DOTs are having like secret book clubs with the books. So there's promising stuff. There are a lot of engineers that felt like I did. They felt like something was wrong. They sort of knew what we were doing often didn't match up with some of their favorite streets or favorite cities or favorite parts of these cities, and they probably felt the same disconnect that I did that led me down these rabbit holes.

Jennifer Hiatt: 4:29

And traffic engineering is really a newer profession, even if, you like, say, compared city planning, which Stephanie and I are planners. So that's perspective we're taking. So can you give a quick history of the profession and how it compares with other forms of engineering? I always found the idea that we call it traffic engineering kind of interesting. So is that even the correct professional title?

Wes Marshall: 4:51

I mean, the terminology I probably use more often is transportation engineering. That's a little bit broader, but it didn't sound as good for the sake of the title, so that's what I went with. I mean, civil engineering has been around like for thousands and thousands of years, right, and civil engineering is usually thought of as structural engineering, like bridges and stuff, or hydrology, you know things like that. It's such a broad discipline, like we do environmental engineering, like we have construction engineering in our department. We even have GIS Transportation, like that element of it. It's only maybe 100 years old, if that.

Wes Marshall: 5:25

So that developed with the advent of the automobile, where we had this burgeoning need for some sort of science to wrap around what we were doing to our streets, our cities, in order to adapt to that new technology at the time. So I feel like a lot of us think this science is so well entrenched and so well done. But that's the thing like, when you actually start looking at it it's like, well, no, even back then we weren't, we knew that, we weren't there yet. But you know, we sort of now think that it's better than it is and I will say it's not our fault, like these thousand page books that were all given. I just assumed, as a young engineer, that whoever wrote these knew more than I did. I assumed they did their research. I assumed that it was steeped in a hundred years of safety science, and that just turns out not to be the case. So yeah, it is a relatively new discipline in the grand scheme of civil or city planning or engineering, or even when you compare it to things like medicine.

Stephanie Rouse: 6:28

Yeah, and one of the terms or requirements that comes out of these manuals that I don't think has much real science behind it and is the most frustrating term that I keep hearing from our traffic engineers is warrants. And you point out in the book that it's really a chicken and the egg situation, where people aren't going to cross a dangerous road but traffic engineers, based on the manual, says we we need at least 93 people, during peak periods or whatever, to cross this dangerous road before we can actually put a signal in. So where did this insane system come from and how can cities get around it when their engineers start citing this?

Wes Marshall: 6:57

Well, you're right, and that's the example I give in the book is that one type of street where you need 93 pedestrians crossing in the peak hour in order to get the warrant for a crosswalk. And you know, my thinking is well, where does this 93 come from? Like, is there a paper they cite, is there some research? And there isn't. Like there's nothing behind it. I mean, I'm sure it's, I guess I hope it's not completely arbitrary, but there isn't much we can base it on. And then when you think about, well, what does that actually mean in terms of our design? You know, I sort of joke like what's the best way to fix pedestrian safety? Well, we make the streets so unsafe that no pedestrians would ever use it. Therefore, we have no pedestrian crashes, but we all know that's not what we want. And the same thing goes when we think about something like this like, well, how do we make it a safe place to cross? Well, we need 93 daredevils in the peak hour to risk their lives to prove to us that this crosswalk is warranted. So when you just think about the logic behind that, it doesn't make sense, like there's very little common sense there. At the same time, you know, maybe a lot of engineers don't really know this Like we feel, like especially the MUTCD. Like you feel like that is the most standard of all our guidebooks I mean the word standard doesn't really fit. Most of them it's really guidebooks, guidelines but in that case you feel like the MUTCD is kind of the highest level towards the standard, because we're not going to obviously do green stop signs or things like that At the same time.

Wes Marshall: 8:21

When I searched through the book, I counted 167 times, I believe, where they use the phrase engineering judgment. Engineers always have leeway to use engineering judgment in like the exact case you're talking about. Like we can say oh look, there's a school nearby. We don't actually need to have 93 people in the peak period crossing to decide to put in a safer crossing or whatever the reason might be. But if you document it, if you have a very logical, rational process, you're taking away the liability worries that I think engineers often have. So we can use engineering judgment, we can use common sense, but I don't think engineers feel empowered to do so. Either they don't know they have that ability, they don't know how to do it, or they're worried about things like liability issues. But you can, we can do better, and oftentimes it's a choice or just not really understanding that we can.

Jennifer Hiatt: 9:16

Even to the legal side of that. I'm a lawyer by training, planner by passion, so every time we would hear one of the engineers be like well, it's a liability problem. Like do you have a rational reason to state why you're okay with this decision? Because that's like, that's the minimum legal requirement for rational basis reviews. Like can you document the rational reason why you're okay?

Wes Marshall: 9:39

putting a crosswalk next to this park seems like something you could meet pretty simply oh, yeah, um, and we had these fears back in the late 90s, early 2000s when traffic calming was sort of new.

Wes Marshall: 9:49

A lot of engineers like oh, we can't do traffic calming, we're gonna get sued. And if you look at the research after the fact, nobody did, nobody got sued. And you know, I lay out the process, I call it the rational process, which is exactly like you're describing, and I link it. I mean it's sort of like tactical urbanism, right, we know we have a problem and we can document that problem with data, like, let's say, it's speeding. If we have speeding data and we know we're trying to fix this speeding problem, and we come up with a list of viable alternatives, right, and we pick one that we think works best. And then we collect data to see if we're actually fixing the problem we'd laid out.

Wes Marshall: 10:25

You're protected from liability. I mean, engineers historically will just throw up a sign, say like even like a sign that says dangerous intersection ahead, and when you first see those, you're like what the heck are we doing? Like, why don't we just fix the dangerous intersection? But when you step back it's like well, why would you do that? And it's because of liability. If you just warn people, it doesn't fix the problem by any means, but it alleviates the liability concern. I'd rather see us be much more proactive and start trying to do stuff that may or may not be in the manual, because we know we have these problems. They're known, we can document it, we can get data on it and let's do better.

Jennifer Hiatt: 11:01

I agree. One of the things that I could not get over reading this book because I am not a transportation planner by any means is that traffic engineers often treat a fatal collision the same as a fender bender for counts and whatever, and that's been influencing our road design for years. Can you explain why we've been doing this?

Wes Marshall: 11:21

Yeah, I mean, well, there's these, you know, from the 1920s or all these industrial accident research. They would have this pyramid and the idea is basically that crashes are proportional in terms of severity. So if you just count, the total number of crashes including fender benders, like that'll be proportional to minor injury, major injury, severe injury all the way up to fatal. So we don't really need to just focus on the fatals. I mean, we'll get the same answer no matter which level we focus on. And it might be true in industrial accidents, but when we translated that to transportation and we made those assumptions that it was true, it turns out not to be the case.

Wes Marshall: 11:58

I mean, I think you all know that when you look around cities, like some of the densest places, you have such slow speeds and you have a lot of, maybe, traffic congestion, so you have a lot of fender benders, right, but that's not where people are dying on our streets. It's where you know the fundamental physics of it, like you need speed, mass and that's what gives us the force and end up having people lose their lives. So you often get completely different answers Like our highways don't have many fender benders, but that's where you have a lot of fatal crashes and vice versa, in cities where you have a lot of fender benders but not many fatalities. So if we made the mistake of assuming that safety is just based on fender benders, you start taking these rural or highway type designs and pushing them through cities and that's where you start getting fatalities there, because we've conflated the problem.

Jennifer Hiatt: 12:48

I find it interesting too, though we had a very bad intersection here in Lincoln. People were somewhat regularly dying at this intersection. Then we put in roundabout and more accidents happened, but nobody died. Some of our residents were like, but more accidents are happening here. This is ridiculous, but nobody's dying. People were dying. You can't win for losing in your profession, really.

Wes Marshall: 13:12

No, it's a matter of priorities. I think I named that chapter. Don't sweat the small stuff, and the small stuff is fender benders. That's a concern for insurance companies. It's annoying and all, and we can improve that too. But let's start with what actually matters are people's lives, and, for whatever reason, we treat road safety, especially things like lives lost on the road, as the cost of doing business, as opposed to like the public health emergency that it really is.

Stephanie Rouse: 13:39

Yeah, it's really interesting on crashes how we treat them based on type of mode. So we just accept the very high rates of traffic deaths on our roads every year, but one plane with a couple hundred people goes down and there are so many more investigations and it's all over the news, but no one's really talking about the massive lives lost on roadways every day.

Wes Marshall: 14:01

The massive lives lost on roadways every day. That's funny. My safety class this week that's exactly what we talked about. I was trying to teach about exposure, like the idea that we can't just look at total number of crashes or fatalities, and it's not really apples to apples. You want to normalize it by something, and we talked through, we tried to actually calculate how safe it is to be in a commercial airline or how safe it is to be on a train versus how safe it is to be in a car, and I think we found the plane was 121 times safer than a car per mile and the train was something like 40 or 50 times safer than a car. But then we talked about exactly what you said, even when the Boeing door stuff was a national issue. Right, this was something that everybody was up in arms with. Pete Buttigieg was out there talking about it, or we had some train crashes, I think, like in Indiana or something.

Wes Marshall: 14:52

I mean same thing, but at the same time every night you turn on the news like somebody dies in a car crash and it barely makes a headline and far more people are dying on our roads and car crashes and pedestrians and bicyclists than die in planes and trains, but for whatever reason, we don't treat it at all in the same way and part of it. You know sort of the difference between like a dripping faucet and like a fire hose. Right, when a plane goes down, it's like 200 people and, yeah, it makes perfect sense why we want to fix that. But even when more than 200 people die in a single day on the roads, it doesn't feel that way Now. So even around the world like, if you look at the numbers, more people die every day on the roads than died in 9-11, but we're not really doing much about it.

Wes Marshall: 15:34

I saw TRB put out a report earlier this week. The graph shows fatalities going up, but fatalities per like vehicle mile travel are going down, and the caption said that roads are safer than ever. I'm like, wait a second, they're not. More people are dying. How is that safer than ever? It's because they're measuring the wrong thing.

Stephanie Rouse: 15:54

We track annually progress on our comprehensive plan and one of the metrics is vehicle miles traveled and crashes per vehicle miles traveled. And after reading that section I was like, oh, maybe we should stop showing that, because that's not really helpful.

Wes Marshall: 16:08

Well, it's helpful if you're looking at the safety, maybe, of a particular road or intersection, right, and you're comparing, like that facility, but it's not helpful for us humans, right? You care about it much more like any other public health measure, and every other public health measure is a per population metric. You know, for a while I was like man. Us traffic engineers were pretty dumb to do that and that's one of the you know, one of the rabbit holes I dug down and I found out that you know, sometimes, like we admitted that we didn't know enough and we're trying to get better, but that is one where it's literally.

Wes Marshall: 16:40

The CEO of Studebaker didn't like in the 1930s, how cars are being made to look very unsafe, so he made the right point that we need an exposure metric, but he just picked the one he liked best. He wrote a book about it. This textbook right behind me, seven Rows to Safety, paul Hoffman, in 1939. And he came up with a metric of measuring it per vehicle mile travel. And then he barnstormed the country selling this new metric to this brand new discipline of traffic engineering. We started using it and 1966 or 65, the USDOT put this into their official metrics for measuring traffic safety, and we've been doing it that way ever since, but at the same time, when you think about what that actually means, there's two ways to improve safety. One is we reduce fatalities or severe injuries. The other way is to increase driving. The more you drive, the safer you seem, and we've been building our transportation system in the streets based on the latter.

Stephanie Rouse: 17:36

And so that's one of the examples of we've just been doing this way forever. We keep talking about bad data going into some of these manuals this way forever. We keep talking about bad data going into some of these manuals and some of them take forever to update. The MUTCD was this very long drawn-out process back and forth negotiations, good changes getting cut. Why is it so hard to change these manuals when we know they're not accurate?

Wes Marshall: 17:57

Well, inertia is one of them, part of them. There's a lot of vested interest in sort of keeping the status quo, not just in transportation but in sort of everything. So there's some entrenched folks on these things. But I don't know, like the MUTCD I'm sure you saw, you know there was that public comment period and do you remember how many wasn't there, like 10,000 or something crazy like that? Yeah, it was high, yeah, and there's some improvements in the latest version that you know still yet to be adopted by all the states, but it's still not what we need or want. And that's the case with all. I mean the Ashford Green Book and a lot of the other ones. The Highway Capacity Manual they're similar. Like you know, I was actually just invited yesterday to speak at the TRB, the Transformation Research Board. We have a giant conference in DC or like 15,000 people there and the committee that looks at capacity they're the ones that are helping write the highway capacity manual. They want me to come speak about.

Wes Marshall: 18:52

I mean the fact that level of service isn't this thing handed down to us on Mount Sinai, to Moses from God. It was sort of haphazardly thrown together in a meeting, just like the meeting we're going to have in DC in January where, like some guy over here is like, oh, we need to do this. And they're like, oh, in the future, we need to make sure we add safety to this. And then the next iteration we remove that sentence. We never added safety. And so when you see how it actually came together, I think a lot of engineers it sort of blows their mind that oh, this wasn't this very rigorous scientific process. This was a meeting just like the one we're in, where people are negotiating for what they think is best for the time being.

Jennifer Hiatt: 19:31

Well, and to that end, so many of these manuals were new to me as I was reading about them, so I had to look them up and read about them in our book, and it seemed that each manual oversteps its purpose in many ways. So, for example, in the book you say that the MUTCD is supposed to provide standards for traffic signs, signals and markings, but it also feels the need to add its two cents on setting speed limits, for whatever reason. Doesn't this ultimately create a confusing situation and make it difficult to apply standards across the board?

Wes Marshall: 19:58

Well, the whole idea behind these from the get go was that, especially in the United States States, where things can differ from state to state, like we need some reciprocity, we need some similarities when you go from one state to the other. I mean stoplights shouldn't flip or stop signs shouldn't look there, all that sort of stuff Like we need to have a commonality. So that was the idea behind them. But you know, over time, you know maybe there's some bloat, maybe there's some. You know, maybe there's some bloat, maybe there's some. You know group think, like you know you've been in meetings and there's a lot of people like it's easier to kind of pick what you think is the safe option as opposed to maybe picking the right option and transportation. I think this is tricky because a lot of the stuff that happens is very counterintuitive. So our theory, you know something basic, like wider roads are safer because it gives people a factor of safety. Um, if you're speeding, if you're drunk or something, you'll still have space to run off the road and you're going to live, and that makes perfect sense. Maybe if you're a structural engineer or if you're someone designing a culvert, mother Nature doesn't care how big I make the beam on this building. It's not going to be any windier, it's not going to rain anymore, so the culvert could be bigger, the beam could be bigger, the beam could be bigger.

Wes Marshall: 21:02

But in transportation people behave based on the transportation system you put in front of them. So, yes, the theory makes sense, give people more space. But if they start going faster, or maybe not paying as close attention to the road or the side of the road, or they look at their phone longer, whatever it might be, I mean, the empirical results aren't matching the theory. And you would think in a scientific discipline we'd fix that, we would learn, we'd get better we. But for some of the reasons you talked about in the question is like we haven't. Like we, that group, think the fact these manuals have been around for so long, the fact that we think they're based in science, has kept us maybe from changing them, from pushing forward, from trying to make them better, and hopefully, what my book points out is they're not as scientific as any of us were led to believe. So we don't need to hold onto them as dearly as we think.

Stephanie Rouse: 21:50

Yeah, and knowing that we're probably not updating the METCD anytime sooner, hopefully that gives engineers more license to use engineering judgment, which is actually built into the manual to use.

Wes Marshall: 22:01

I hope so. I mean, I know this book is not specifically meant for traffic engineers. I hope they read it. I hope they do better. But I also want to give people in positions like you, or advocates or people like that, enough ammunition to maybe more effectively argue with an engineer, like I've heard you all in your podcasts complain about. You put these great plans together and then where do you get your pushback right? So often not even from the public is from the engineer Like oh, that looks great, but we can't actually do that. So you know you get enough information from my book where like oh, like what he's actually saying there, what she's saying there isn't really a standard. Like they do have engineering judgment and you can point this out to them even if they don't read the book. But I'm glad to hear they did.

Stephanie Rouse: 22:43

Yeah, we'll definitely pull in some sections and forward them on the next time they push back on our ideas. So no discussion of transportation is going to be complete without addressing autonomous vehicles, and you rightly point out in the book that this isn't the silver bullet that's going to fix everything. Even if we could get everyone into an autonomous vehicle and I hadn't really thought of it too, about just beyond the affordability piece there's going to be people out there that don't trust this technology and will never adopt it, and so we're never going to get everyone in autonomous vehicles. So there's still going to be plenty of us with our own autonomy in a vehicle or walking or biking. What are some of the other red flags with this reliance on autonomous vehicles that you discuss in the book?

Wes Marshall: 23:25

I think if you look at the benefits of autonomous vehicles, you know the thinking is like human error is a big problem in our crashes. It's like 90, they blame it on 94%, but that's something I sort of disprove in the book too and that we're going to get all these benefits within this autonomous system. So we're not going to need parking, we're not going to need whatever it is. We get all the benefits. But if you look at that list of benefits, you only really get them if every car on the road is autonomous. I remember I was in Australia for sabbaticals, I was in Sydney and they used to do this thing called city talks and they brought in these outside speakers, which were great and hundreds of people came to this. And I saw one by this guy from MIT and he was showing this awesome animation of, like this conventional intersection where delay is happening, cars are backing up, and he showed an autonomous intersection where every car is getting a reservation and just flying through this intersection like crazy. And he declared the latter one the future of urbanism and he got the standing ovation from like 200 people. I'm like wait, what? Like what if you have one human driver or one pedestrian or one bicyclist. Like that doesn't work whatsoever. Like this might be the future of the middle of nowhere, but it is not the future of cities. And when you start thinking about even if we can get the technology right, like yes, waymo's ahead of other folks and doing the robo taxis in San Francisco and places, but you don't get the same benefits when it's just a few of them, and how can we get everyone to do it? I mean, you know, I joke that there's a reason why there's like 11 Fast and the Furious movies and they've made like $10 million or whatever it is because people love driving and there's a huge culture around it. So to get everyone to shift isn't often just the technology problem, it's a social or cultural problem and it might not go as far as like the gun debate goes, but you're going to have some people saying you're going to pull this steering wheel out of my cold dead hands and like we're not going to get there right. So there's so much behind it. And then, if you, I read Peter Norton's great book Autonomorama recently and like he basically brought this back you know 50, 60 years where we've had this technological carrot kind of dangling in front of us, and it's always five years in front of us and it's been five years in front of us for 60 years and it's still there. It changes what that technology is, but it's still hanging in front of us. And it's been five years in front of us for 60 years and it's still there. It changes what that technology is, but it's still hanging in front of us. So there's a lot of people I know that are great engineers but they just don't really worry about safety because they feel like AVs will fix it. And it's just not true. It's easier said than done. It's much more complicated in terms of the social, cultural than we think. Even if we get the technology right, yes, we'll reduce some types of crashes, but with every technology over the course of history it leads to other types of errors. So I mean, just interacting with these different technologies isn't the same.

Wes Marshall: 26:17

10 years ago I remember driving up to the mountains with a neighbor of mine. So I live in Denver and if you want to go skiing or snowboarding, go an hour plus west. Then there's tons of snow and tons of that kind of stuff. And at the time I think he had a new BMW and he was just changing lanes willy nilly without looking. I'm like man, what are you doing? Shouldn't you look? He's like oh no, the car will tell me if there's a car in the adjacent lane. So if he added that technology to what he had done before, if he was still looking over his shoulder and using the mirrors, and you layer that technology on top, it would be safer.

Wes Marshall: 26:49

But when you replace the technology, maybe not. Our cars get dusty in the mountains, so maybe it's not working or maybe the sun is a certain glare. The technology can't see that car, whatever it might be. The safety benefit isn't as clear cut when you think about it this way. And even those cars now that are supposed to stop for pedestrian I mean, the research shows they don't work in certain lights. They don't work as well with darker skin. You know these technologies are kind of a little bit racist when you think about it that way and we don't want that either. So if we start shifting how we behave based on technology and this relates to the last points we were talking about it's not as clear-cut.

Jennifer Hiatt: 27:28

So it's, it's just not that simple every time I read about technology that's supposed to be able to like identify people and how it just hardly ever identifies people with dark skin. I think about the episode from the tv show better off dead. If you haven't seen it, everybody should go. Watch's funny. Got canceled after like two seasons, but they have a whole episode where it's like the cost benefit of putting in all of this automated stuff versus the uncomfortableness of their employees of color. It's like they couldn't wash their hands, lights didn't turn on, cars don't stop for them. This seems like a bad future. Plus, I've seen too many dystopian movies and read too many dystopian books. You're not putting me in an AV car.

Wes Marshall: 28:06

Yes, my wife watched that show. That's the one on Netflix. It starts off, didn't it? Like the friend's husband died in a crash, or something like that I saw a couple of those yeah.

Jennifer Hiatt: 28:14

Speaking of cars, I know transportation engineers don't design cars, but shouldn't you guys have maybe some kind of say in that.

Wes Marshall: 28:38

So we create roads you can drive 120 miles per hour on. But why does any car reach 120 miles an hour when nowhere in the country has a speed limit over 90? It doesn't make sense. I do have some chapters about cars and how fast and big they are, and you know I joke. When I was 16 and I bought myself a car, I was pretty thankful it couldn't go more than like 75 or 80, because it was a pretty crappy car, because at that time I drove as sort of fast as I could everywhere I went. And now if you look at the odometers on a lot of cars they're like 140, 160, 180. I've seen a sum of 220 and 240. We don't need that unless you're like driving NASCAR or Formula One.

Wes Marshall: 29:07

But there is, for whatever reason, like thinking that more power equals like more safety. I mean there's also social, cultural issues. You know, talking about the Fast and the Fur came to Denver like people were crazed about how fast they go and try to do some geofencing around, like our 16th Street Mall, which is a pedestrian zone, to make sure these scooters were forced to drop down to three miles an hour in that zone. I know DC does something similar. They couldn't get it to work here in Denver but for whatever reason, everyone was okay with that.

Wes Marshall: 29:41

But when you say the same thing about cars, people lose their mind. Like oh, that's un-American, like you can't tell people what to do and I know, for whatever reason. With things like even red light cameras, speed, the conversation devolves into freedom. Big brothers watching me Like the conversation is never about safety. If we can keep the conversation on safety, we'd be better off.

Wes Marshall: 30:02

You know, if safety really was our first priority, our cars would be bubble wrapped. They would go no more than maybe 20 miles an hour in cities. But it's not. You know there's a group of people that are trying to make money off of cars, but we've also built a transportation system where most people live in a place where driving is really the only viable option. And then when you think about the rational decision of those folks, like driving in a big SUV makes the most sense too right, and to me I feel like it's on engineers to fix that, on transportation planners and city planners to fix that. At the same time, there is a rule for policy in terms of limiting speeds or limiting car size, or even just making folks that use a bigger, badder car pay more in insurance right. Use a bigger, badder car, pay more in insurance, right. Like there is more risk that you're putting out there into the world when you drive a truck like that than if you drive like a Mini.

Wes Marshall: 30:50

Cooper or something right that's not anywhere embedded into, like the costs that are put on to folks that do that.

Stephanie Rouse: 30:57

When you're talking about, if we really want things to be safe, we wouldn't be driving more than like 20 miles an hour. And it was really interesting. I had friends from Minneapolis come in last weekend and when they got there they were like, oh, is it 35 miles an hour on your street? And it's kind of a sort of residential, but it's technically like a collector street in Lincoln, but it feels more like a residential street. And I was like yeah, no, it's 35. And they're like, oh, that's weird, it's 25 everywhere in Minneapolis now. And I was like, yeah, no, we have streets that run through town that are 45 miles an hour, like we are not really prioritizing safety in our community, like Minneapolis and some other communities are.

Wes Marshall: 31:33

Yeah, I mean, if you look at the data, you know. I mean there's a lot of different numbers that look at it, but in general, like a pedestrian that gets hit at 20 miles per hour, it's maybe a 15% chance of dying. At 30 miles an hour it's closer to 45%. At 40 miles an hour it's like 80, 85%, right? If you just know those numbers and if you say safety is our first priority, it's obvious what to do. But we're not doing that in most places.

Jennifer Hiatt: 32:00

I think the diagram was in your book or it was in some extra research I was doing to do, but we're not doing that in most places. I think the diagram was in your book or it was in some extra research I was doing to prepare, but it showed like a big truck and a car and the impact zone on a human body and I am five foot tall and never really thought about like where a car would hit me if I got hit and that was like a terrifying realization that my head isn't even in like a sight line of maybe half of the cars that people sell these days or buy or drive.

Wes Marshall: 32:27

Oh yeah, I've seen some. I don't have any images in my book whatsoever, so there probably wasn't one you saw there, but I talk about that exact issue, right?

Wes Marshall: 32:34

So if you are hit by like a Honda Civic from 20 years ago, you get hit in the legs, you roll up into the hood, you may hit the windshield, you might break your legs, but you're often going to be okay.

Wes Marshall: 32:44

If you get hit by an SUV today, you get hit like in the chest, you get knocked down, your head hits the pavement and you get run over and you're much more likely to die. I'm doing a talk at the Safe Routes for School conference in a couple of weeks and, like one of the things I'm thinking about is I mean just the fact that like even something design-wise as simple as where we put the stop bar in front of like a stop sign, like you know you know there's a lot of videos on this like in a lot of our SUVs today, like there's that one from Indianapolis where they had 13 kids sit down in front of that car and the driver couldn't see any of them, right? Well, how would you design the intersection differently? Well, you should push the stop bar back like 20 feet, right? If our car is going to be this big, if kids are this little, let's design this differently and daylight the intersection, push the stop bar back. There's simple, obvious, common sense things to do, but we're not doing them.

Stephanie Rouse: 33:35

So another term that comes from the manuals that deals with speeding is the 85th percentile another one of my least favorite terms I keep hearing from our engineers. So the concept is you know, we match our speed limit based on what 85% of the drivers are going, then the drivers take that speed limit and up their speeds, and then it's just this continuous cycle of raising speed limits. Why is it so hard for engineers to just design a street for lower speeds, that they actually want to see an action, versus waiting for drivers to drive a speed and then adjusting?

Wes Marshall: 34:07

Well, this is a good example of the theory kind of trumping empirical results. We have this theory that as long as all drivers are in the same maybe 10 mile an hour pace, like most of our drivers are in that same short pace, that's how we, like most of our drivers are in that same short pace. That's how we get to safety. It doesn't matter if that pace is 80 or 20, safety is better, right, and that research goes back to David Solomon, like this older research when you look at the original study that led us to think that it's been debunked half a dozen times over, based on just these rural roads in Texas, and he showed something that, like these slower cars are hundreds of times more dangerous than the faster cars, and it just wasn't true. If you dig into the actual data, it's really just people turning in and out, of, like gas stations on these rural roads that are getting hit from behind by the faster cars. And all the empirical results since then shows us that higher speeds leads not only just to more crashes but worse overall safety in terms of fatalities and severe injuries. But that thinking has stuck and we have this mantra if you look at, like in the MUTCD, how we set speed limits. It's based on the assumptions that drivers are reasonable and prudent. Whatever road you put in front of them, they'll tell us how fast and safe to drive. Like is that true? Do you feel that's true? Probably not, but that's still what we're doing. So we let drivers vote with their feet as to how fast the speed limit should be.

Wes Marshall: 35:30

And I mean, I give some crazy examples in the book, like there's one from California where these college students at Cal State Northridge were killed on the road right next to it as pedestrians. And you know, like, oh, we got to do something about safety. So what do they do? They did a safety study, they did a speed study and they raised the speed limit. It's like, wait what? We raised the speed limit on this road next to a college because a pedestrian was killed.

Wes Marshall: 35:52

And that's how you're going to fix safety. And guess what? More pedestrians were killed and they did it again. And it just doesn't make any logical sense. And there's the other example from Utah, where they had this problem with wrong-way drivers on their highways and their thinking of how to fix that safety problem was to do a speed study and raise the speed limit. It's like how in the world would that possibly fix this wrong-way driver problem? But that's the thinking is that this 85th percentile is the way to safety, and it's just not true and the research doesn't back it up. But we were taught that this is how we get safety, so that's why we're still doing it.

Jennifer Hiatt: 36:29

Bothers me.

Wes Marshall: 36:30

It should. That's the thing, right. It bothers me and that's why I probably a tinge of anger in a lot of my writing, because I'm angry about some of this stuff, right.

Stephanie Rouse: 36:42

So a lot of it came through in your footnotes and I loved all of the references and the snarky comments. I never read footnotes, but those ones I definitely did.

Wes Marshall: 36:49

Thank you, it was good to hear.

Jennifer Hiatt: 36:51

Never skip the footnotes. So, as you mentioned at the top of the episode, though, at the end of the day, you're not actually saying that transportation engineers are intentionally designing bad roads or actually going out of their way to try and kill people. So, ultimately, what steps are you proposing? The profession needs to start doing better for our cities and people who live in them.

Wes Marshall: 37:10

So I link it to medicine and doctors. Right, doctors have been around for similar to civil engineering like 5,000 years, let's say, and it wouldn't be hard to say, you know, the first thousand years after Hippocrates. Let's say, and it wouldn't be hard to say, you know the first thousand years after Hippocrates, that they were probably killing more people than they saved. But it's an empirical science, they were getting better, they were learning, they're doing trials, whatever have you in the medicine world, and now I mean it's not perfect, but they're still trying to get better and better. Like that's the thinking Traffic engineering, transportation, engineering. We're only 100 years old and what I'm saying is we're still in that stage, like we're still killing more people than we save. We just don't know it. And our problem is we have become less of an empirical science. Like we're still steeped in these theories that have been disproven and to some extent it feels more like a religion than a science. So how do we get better? We need to go back to being a science, get back to being an empirical science. Do things like the rational method or tactical urbanism. See what works, test stuff, use engineering judgment and learn and get better.

Wes Marshall: 38:16

And look around at the cities, the streets that work. I know I grew up right near Boston and that's what kind of led me down some of these paths is the stuff I was building as a consultant, you know, worked as like seven years in that space was never as good as what I saw around me. I was like, well, why can't we build a street like that? And you look it's like, well, it's illegal to given, you know, certain guidelines or certain parking minimums or level of service, and these are our favorite places and cities that we have engineered out of being a possibility. Then we look at, well, where do we put most of our engineering?

Wes Marshall: 38:53

Like in most cities, the arterial network that the DOTs are often in charge of are our most engineered roadways. That's where we put all of our science and thinking. And then you look every city that's done one of those high injury network studies where 50 or 60% of deaths take place in like 5 or 6% of the roadway. Which roadways are we looking at with that? It tends to be those same arterial roadways where we put all of our engineering thinking into, and you see the disconnect. It's not hard to see it. So that's what we need to start doing is getting back to being an empirical science, getting back to actually looking around and seeing, well, what works. What is maybe the corner radii of this street that we all love and it works today? What is actually that measurement? And you see, well, we can't even build that today. Well, maybe we should change. What we can build today and that is where I hope it starts going is more in that, empirical as opposed to theory-based direction.

Stephanie Rouse: 39:54

I would love to see that as well. And, as this is booked on planning, what books, in addition to yours, which we all recommend everyone, of course check out that you would recommend our readers read?

Wes Marshall: 40:05

Yeah it's funny, while I wrote the book for like the three plus years there, I didn't read any of the transportation books. I didn't want to be influenced by the other books that were coming out. So I kind of went in my cave and did my stuff During that time. I read a lot of fiction and stuff, but not anything transportation. I actually stopped listening to even the smart podcasts. I only listened to really dumb podcasts for a few years in there. When I came out of the cave I started trying to catch up with everything.

Wes Marshall: 40:32

So I know some of these authors have been on your show, like Angie Schmidt and like Dan Piakowski and Jeff Spex, like his new Walkable Cities book, human Transit by Jared Walker, the second edition I just read recently the ones I was surprised how much I loved. I just read Anna Ziver's when Driving is Not an Option and Veronica Davis I think you had on your show too Her Inclusive Transportation. I loved that book. Going back in time, like some of the, I first got into this world, like Donald Shoup's work was always. I started getting into that even before his High Cost of Free Parking book came out and you can maybe see some of his same approach. They're kind of shedding light on the lack of science behind parking. That I do with a lot of other things Transit, metropolis, the Robert Severo book from like the late 90s, I think. There's so many books out there. I'm actually curious more what you guys are reading these days.

Stephanie Rouse: 41:24

You can see what we're reading on our show Two books. We're kind of getting into a groove of two books a month which is hard to read, much else than what ends up on this podcast.

Wes Marshall: 41:32

Yeah, I'm sorry. My book was like 400 pages. That makes it harder.

Stephanie Rouse: 41:36

It was a pretty good read, though Just the way you wrote it made it digestible.

Jennifer Hiatt: 41:42

I was going to say it went very quickly. When you pick it up it looks hefty, but when you start reading through it it's very simple to get through. Like so I can study easier to digest.

Wes Marshall: 41:50

Yeah, I think I read so much, I know what I like to read and I know what I don't and I know what it feels like when a chapter is like two hours long and it just feels like a slog and I went for the short chapter. So there's like 88 short chapters. Each one has like a beginning, middle and end and then they're kind of grouped into parts and those parts of beginning, middle and end. So I got some pushback from some of the publishers I talked to. They wanted like a traditional introduction or a traditional conclusion. I'm like, oh my God, I'm getting bored just thinking about that. And I had sort of a vision. I wrote the whole book first, before I even talked to publishers. I was like, no, this is what I want, we're not doing that. So I tried to fight the fight on that and I like how it turned out. So I'm happy to have done so.

Stephanie Rouse: 42:33

I totally agree with your style choice and I'm glad Island Press picked it up and saw the vision.

Wes Marshall: 42:40

It makes a big difference when you sort of have a publisher that's on board with that vision. They didn't push back on some of the footnotes, though they're like do you really need? Like to mention the simpsons again, I was like do we really need anything like?

Jennifer Hiatt: 42:53

no, we'll.

Wes Marshall: 42:54

We'll make sure, when we touch base with island press, to tell them that you did need those footnotes every single one of them I literally wrote a book about like kids dying on the road, right, like it would be a tough, tough read if you didn't. You know, maybe add some levity. Or you know, also, I'm a academic, so most of my writing's been in peer-reviewed journal papers, right, and you can't put your personality in those. So I was like, well, here's my chance to just do something that I would read even if I wasn't in this space, right, and you know, and if it makes some of my friends laugh, great, like this is what I would read, this is what I would like. And it seems like people have responded well to it. So I'm happy to have seen that happen.

Stephanie Rouse: 43:32

Yeah Well, wes. Thank you so much for joining us on Booked on Planning to talk about your book.

Jennifer Hiatt: 43:43

Killed by a Traffic Engineer. Thank you both for having me. This was fun. We hope you enjoyed this conversation with author Wes Marshall on his book Killed by a Traffic Engineer shattering the delusion that science underlies our transportation system. You can get your own copy through the publisher at Island Press or click the link in the show notes to take you directly to our affiliate page. Remember to subscribe to the show wherever you listen to podcasts, and please rate, review and share the show. Thank you for listening and we'll talk to you next time on Booked on Planning. Thank you.