The number of fatal crashes in America is up by about 7 percent over the past decade. But in roadway work zones, it’s up by more than 40 percent. Senior Research Engineer Jerry Ullman explores why those work zones are dangerous not only for those who work in them, but for those who navigate them as well.
The number of fatal crashes in America is up by about 7 percent over the past decade. But in roadway work zones, it’s up by more than 40 percent. Senior Research Engineer Jerry Ullman explores why those work zones are dangerous not only for those who work in them, but for those who navigate them as well.
Welcome. This is Thinking Transportation. Stories about how we get ourselves and t he things we need from Point A t o Point B, and all that can happen in between. I'm Bernie Fette with the Texas A&M Transportation Institute.
Bernie Fette:All of us face the risk of a crash every day that we venture out in our cars and trucks, and that risk increases substantially if our trip involves passing through a highway work zone. We can expect those environments to present a safety challenge for as long as new roads need to be built, and for as long as current roads need to be maintained and repaired. Few people know that better than our g uest for this episode. J erry Ullman is a senior research engineer at TTI, and he's dedicated most of his career to finding ways to make roadway work zones function more safely and smoothly. Thanks for joining us today, Jerry.
Jerry Ullman (Guest):Glad to be here.
Bernie Fette:So, fatal crashes in work zones are up by more than 40 percent over the last decade or so. The number of deaths increased by more than 50 percent. Injury numbers up, too, though not quite as dramatically. Many of us might think that construction workers account for most of those deaths, but that's not the case, right?
Jerry Ullman:Well, that you're absolutely correct. I think the last time we did an analysis, something like 80 to 85 percent of the fatalities are motorists, passengers in vehicles. So workers are certainly a part of the fatality concerns we have, but they're not the only ones that are at risk in work zones.
Bernie Fette:Why is this happening? Why are the numbers going up? Is it just that people are driving more miles, more construction sites?
Jerry Ullman:It's a multitude of things going on. As construction spending has increased over the years, as vehicle miles of travel has increased over the years. And just that exposure probably accounts for some of the increase. We're concerned about distracted driving, we're hearing stories or anecdotes from other states, and even here in Texas, where we're having an increase in number of our construction vehicles, you know, even those with the truck-mounted attenuators on the back of them are getting struck. Our hypothesis is a lot of that's due to more and more distracted driving, but other factors as well. The increase in traffic also leads to more disruptions when you have work zones-- disruptions and traffic slowdowns, and that kind of a thing that contribute to all this.
Bernie Fette:How much then does crash likelihood increase when someone drives into a work zone as compared to just traveling down the highway or street? Is that a fair question?
Jerry Ullman:It's a fair question. It's, a little challenging to answer. Each work zone's very unique. Gets put into a location that in and of itself has a, you know, a unique crash history. And then when we add devices in there and we'll put equipment out there, we put workers out there. We do see relative to what normally is going on in that roadway section, crashes do tend to increase. Depends on the type of work zone that's been put out there. For example, if it's a major reconstruction project and most of the work is behind barriers, we've just put some barrier walls out, close to lanes and stuff and shift them around. We might see 10 to 20 percent increase in crash risk. If you look at a lane closure where they put out an arrow, they put out channelizing devices to move you out of one lane into another lane, you could see as much as a 66 percent increase in your crash risk going through that work zone relative to that roadway section without a work zone there. And then if we, because of the characteristics of the roadway and what we have to do, work-wise we start backing up traffic. This data's a little less definitive, but you can see crash risk go up by as much as 4 or 500 percent.
Bernie Fette:Oh, wow.
Jerry Ullman:If we have a backup, that is a big contributing factor to crashes in work zones.
Bernie Fette:Is there a particular type of crash that's most common across work zones in general?
Jerry Ullman:Rear-end collisions for obvious reasons, the backups that particularly in rural areas where your drivers don't expect come over a hill and have to stop. That's a big situation that we'll see a lot of rear-end collisions tend to occur because of that. On Interstate facilities, where we close lanes, we might see increases in sideswipe crashes.
Bernie Fette:With regard to those, the ones that are most common, the rear-end crashes you and your colleagues over the years have come up with some ways to help reduce those, isn't that right?
Jerry Ullman:We helped Texas Department of Transportation assess and implement some technologies that were in place, but weren't being widely used across the country. The use of what we call a smart work zone systems, let's call them technology, sensors, and electronic signs and those kinds of things that we connect together and monitor traffic conditions. And then when we detect a backup occurring, send a message out to that sign to say,"hey, there, stop traffic ahead." Uh, which tells the approaching drivers to be more alert in slowing down and that kind of a thing.
Bernie Fette:And that message goes back what a mile or more to people who are not even close to the work zone?
Jerry Ullman:That's, that's the idea, is to prepare them prior to reaching the back of the queue.
Bernie Fette:Have you seen good results from that system that you put together that offers that advanced warning?
Jerry Ullman:Yes, actually we assisted the Waco district of the Texas Department of Transportation and the implementation of an end-of-queue warning system over the last several years during the reconstruction of Interstate 35 through the district and the deployment of that end-of-queue warning system, that includes the use of temporary portable rumble strips that are laid out on the pavement by the electronic signs I was talking about. Collectively, using that technology achieved about a 60 percent reduction in crashes that would have otherwise occurred at those lane closures if the systems had not be deployed.
Bernie Fette:That's pretty big.
Jerry Ullman:Yeah.
Bernie Fette:When we were talking a minute ago about the causes, one of the things you mentioned was more miles traveled and more construction funding out there, which brings up the question of what might be happening in the future. There's federal infrastructure legislation that's being talked about and might bring about more infrastructure investment, and therefore more construction zones. Is it likely then, or with something that we shouldn't be surprised to see a higher crash numbers as a result?
Jerry Ullman:Yeah, I think we should be prepared...
Bernie Fette:At least prepared?
Jerry Ullman:... prepared to see that. It will depend on the types of projects, and more importantly, the characteristics of the locations where these go,'cause that really drives the numbers themselves. I think the other thing that will be challenging though, is once you introduce a sizeable investment, there's going to be a lot of new companies starting up and, and folks who probably aren't as, have a lot of experience in doing road construction and road maintenance work. It's going to be very challenging to make sure that they are sufficiently trained, truly understand the risks, know how to protect themselves. And that owner agencies themselves are taking the steps necessary to implement strategies that will mitigate some of these crashes to the extent we can.
Bernie Fette:That experience factor that you're talking about, I think relates pretty closely to something else that I was hoping to ask you about, which is how much thought typically goes into deciding how to set up a roadway work zone, because on the surface to some people, it looks like it would be pretty simple. It's really not all that simple.
Jerry Ullman:No. It's based on years of research and experience. Trial and error in the field. You have standards that are developed by the Federal Highway Administration and most state DOTs have standards as well about how to set up a work zone, depending on again, the type of roadway you're on and the type of work you need to accomplish. So simple maintenance work, for example, repairing a guard rail section, setting that up, you can go right to the standards and say, okay, I need to put these signs out at these locations, put these drums or cones out at these locations. Pretty straightforward, and can be implemented almost immediately after deciding kind of where you're going to go. You get into major reconstruction projects, though. Then it becomes much more of a engineering analysis, design analysis taking into consideration what hazards are going to be in what locations, making sure you've got the right positive guidance, that'll help lead drivers through the maze if you will, depending on again, the setup and that kind of a thing. So it, it can become very complicated. Take quite a bit of technical know how to put one together correctly,
Bernie Fette:Lots of complexity and much of the complexity that you were just talking about has to do with engineering standards and just physical requirements. But one of the other things that you might have to take into consideration is driver behavior. How much of what you have to figure out-- how much of that task-- depends on understanding human driver behavior?
Jerry Ullman:Oh, it's essential to be able to design an effective temporary traffic control plan and implement that. The standards and guidelines that I was mentioning previously are that, and the recognition of all temporary traffic control is that that's a starting point, but what you have to look at your site conditions, you've got to think about characteristics of the target drivers that'll be there. Are they local drivers or the Interstate? Is it predominantly large trucks? Whatever it is, and then take into consideration, hey, if I've got these characteristics, maybe I need more signs than what the minimum is required, or I need to provide a slightly different way of shifting traffic because I've got a lot of, you know, large trucks coming through here. Those kinds of things. So knowledge of human factors, driver behavior is essential.
Bernie Fette:So whenever you talk about the locations of the zones and how they need to be designed based on driver behavior, that could be influenced in part by let's say if there was a work zone in the vicinity of an entertainment district, where there were lots of bars and restaurants. So you might have to be concerned with the possibility of impaired drivers in a location like that? Or even places where drivers, depending on their age might be more prone to smartphone use. Are those, some of the considerations you have to take into account?
Jerry Ullman:I would say less so about the smartphone location, just because we still don't have a real solid understanding of maybe differences in where that's used and you know, that kind of thing. So that's always a concern in setting up and designing a work zone. Your statement about proximity to, you know, entertainment districts. And that certainly comes into play, recognizing when perhaps with work zones near those areas. You just decide you're not going to be out there. You know, as a contractor on Friday, Saturday night, it's just too dangerous to be out there and maybe designing your traffic control a little bit more, again, going above the minimums, just in case, you know, it could be even the least bit confusing and, you know, adding a little more guidance in channelizing devices and stuff to verify:"Don't go here, definitely go this way. This is where you need to go" kind of thing.
Bernie Fette:Just for a little more clarification?
Jerry Ullman:Yes.
Bernie Fette:What do you think are the ways, biggest one or two ways, that work in construction work zone safety and operations, the biggest ways that it has evolved over the last, say, half a century?
Jerry Ullman:Well, a half century ago, we were kind of shooting from the hip as far as temporary traffic control. In fact, we were just getting done using, I don't know if you ever heard of the smudge pot?
Bernie Fette:Yes.
Jerry Ullman:Where it was, you just lit a, uh, basically a giant candle and that was the guidance at night. And that kind of thing. We've come a long way.
Bernie Fette:Just to clarify, those smudge pots were lit up and then just placed in a line or in a curved line just to help guide drivers through a nighttime zone like that. I mean, it was that? Okay.
Jerry Ullman:Yeah. That's what we had. Yeah. So we've evolved with much more human again, human factors-based research led to the development of the standards we now have at the federal level. And at the state level, we've got a number of safety countermeasures have been introduced and tested and evaluated. The end-of-queue system we mentioned previously, you know, has reducing work zone crashes. There's been a lot of analysis to better understand how work zones affect safety. So we've got better estimates of what kinds of increased crash risk we might expect as a function of, of the roadway. Then I would also say the efforts to develop temporary traffic control devices that are crashworthy has been a big improvement in safety over the years.
Bernie Fette:That's over the last half century. What about the next half century? What do you think are the most pressing questions about work zone safety right now that research could help to figure out.
Jerry Ullman:The big gorilla in the room right now is the evolution of the connected and autonomous vehicle fleet that we know is coming. And anybody that's working in that area will say that how to deal with work zones is going to be one of the biggest challenges. The systems that have been developed work pretty well when you've got a nice pre-mapped out roadway segment, you've got nice lines on the payments. You've got nice, good signs and all those kinds of things. You introduce a work zone where you're shifting, where they're supposed to drive. We've got deliveries coming in and out. So they're all kinds of unexpected turbulence in the traffic stream, the dirt and grime from work activities degrades signing retro-reflectivity. The dirt on the pavement itself starts to obscure the lane lines. We start rubbing those lane lines off'cause we're using temporary paint'cause we don't want it to be there after we're done. You start have a, the connected and autonomous vehicles really, they can struggle and will struggle, you know, with a lot of our work zones. So figuring out what we have to do from the infrastructure side to support those types of technologies is going to be a major lift over the next several years to figure out how best to do that.
Bernie Fette:You talked earlier about making smart work zones. It sounds like the challenges you've got with connected and autonomous cars is going to take that challenge to an even higher level to make those zones even smarter.
Jerry Ullman:Exactly. Smarter, responsive, and accurate. One of the things we have right now are fairly, in a lot of places, general guesses about where work zones are, in what conditions those are, and that kind of a thing to adequately support the connected autonomous vehicle fleet going forward. Could almost need up-to-the-minute kinds of information being disseminated about,"Hey, I just closed the lane or I just moved the lane or we have workers showing up today, the speed limit's going to be dropped by 15 miles an hour." Whatever those types of things are. We got to figure out how to institutionalize that as part of the bid packages that other agencies such as the Texas Department of Transportation start issuing, so that capturing and keeping that kind of information current as work progresses w ill be, again, very important to the success.
Bernie Fette:Yeah. Keeping that information current, whenever you are acknowledging at the same time that the circumstances and the needs for a particular work zone could change literally day by day.
Jerry Ullman:Yeah. Even multiple times within a day, depending on what's going on.
Bernie Fette:Yeah. When the National Work Zone Safety Information Clearinghouse was established almost 25 years ago, the idea of a clearinghouse, a repository of information, wasn't necessarily new, but the idea of having a repository like that on the internet was new because the internet itself was still pretty new at the time. How has that progressed over those years in your judgment?
Jerry Ullman:When we kicked it off, you know, started the initial design, you're right. The internet was really just this new thing and the thought was still,"Hey, we're going to do contacts via phone, maybe this new thing called email. We could probably use that as well, but you can certainly write us a letter and send it to your question." And that's where we were at, the idea for the clearinghouse came about. And so that the focus then, because the internet was not the tool that it is today, we were reaching out for hard copies of reports and manuals and plans and those kinds of things and bringing them in and just making folks aware of this is the material that we have available, if you're looking for it. It's evolved many ways out of how the internet has evolved to where nothing's really hard copy any more in terms of this. Our role from the clearinghouse, which initially was to make things that nobody could get access to available for those that were looking for that kind of information. We're now to the place where there's so much information that's accessible through the internet, the clearinghouse is looking for ways to collect it and organize it and disseminate it in a way that makes it useful. You can easily get overwhelmed with all the information that's available, safety-related as it relates to work zones.
Bernie Fette:And how do you see it going forward?
Jerry Ullman:As part of the clearinghouse operations over the last 25 years, we periodically go through a redesign process just to try to evolve ways of doing things 5, 6, 7 years ago on the website. What's the right way to do things now? And so we are actually in a redesign effort. So sometime early next year, we'll have a new look and feel to the clearinghouse.
Bernie Fette:You probably could have gone in a few different directions whenever you decided to get into this transportation field. What is it that makes you get up and come to work every day?
Jerry Ullman:(Laughs). Uh, that's, well...
Bernie Fette:The dream of fame and glory, I know.
Jerry Ullman:No. The, the, the fact that there's so many things I haven't got done, or behind on, I need to go to work to get, get caught up. So no, no, seriously, the transportation field, then civil engineering, was one field where even as I was going through college, the recognition that people change and that you're going to have an area where you'll never get it completely figured out, if that's the best way to put it. You know, we can break beams and we know how to design hydrology systems based on standard engineering principles, but transportation, because of the fact that you're introducing a human driver and human attributes for those drivers, the research side of it becomes so essential just to figure out how do you interact or how do you design and operate a transportation system, dealing with such a wide range of possible responses by the motoring public. So.
Bernie Fette:You sound like you're in a place where you don't really have to worry very much about your work ever becoming boring.
Jerry Ullman:It hasn't been for the last 37 years. I don't think it will start probably anytime soon.
Bernie Fette:Yeah, probably not. Jerry Ullman, senior research engineer at TTI. Jerry, thanks. This has been very instructive and informative. We appreciate your time.
Jerry Ullman:Thanks for having me.
Bernie Fette:Highway works zones aren't only dangerous for those who make a living by laboring in them. They're also quite dangerous for those of us who navigate them. Better engineering and new technology have led to safety improvements in those environments over the years, but we can expect safety challenges to persist even as our roadway networks expand, and as our car and truck technologies advance. Thanks for listening. We hope you'll be back next time for a conversation with Katie Turnbull and Neil Pedersen and a discussion about what research has done for how we moved about in the past and what it can promise for how we do so in the future. Thinking Transportation is a production of the Texas A&M Transportation Institute, a member of the Texas A&M University System. The show is edited and produced by Chris Pourteau. I'm your writer and host, Bernie Fette. Thanks again for listening. We'll see you next time.