Talking Michigan Transportation
The Talking Michigan Transportation podcast features conversations with transportation experts inside and outside MDOT and will touch on anything and everything related to mobility, including rail, transit and the development of connected and automated vehicles.
Talking Michigan Transportation
As road funding talks continue, a look at pavement forecasts
On this week’s edition of the Talking Michigan Transportation podcast, a conversation with a trunkline pavement strategy specialist about how the work in his area helps inform investment decisions.
Tim Lemon, who works in the Michigan Department of Transportation (MDOT) Bureau of Transportation Planning, talks about how pavement condition is measured and how the data is used.
He explains that remaining service life (RSL) is MDOT’s primary pavement condition performance measure, which indicates the number of years before the pavement is anticipated to reach poor condition. It informs decisions about priorities and which roads and bridges to address.
He also explains that while state trunklines (I, M and US routes) don’t account for the majority of road miles in the state, they carry 53 percent of total traffic and more than 75 percent of commercial traffic in Michigan.
Hello, welcome to the Talking Michigan Transportation Podcast. I'm Jeff Cranston. With talks heating up over both a budget for Michigan for fiscal year 26 and, tied into that, what might happen with the roads package a longer-term plan to fund the state's roads, I thought it would be a nice time to talk to Tim Lemon, who works in the Michigan Department of Transportation's Bureau of Transportation Planning. He is a trunk line pavement strategy specialist and is a font of knowledge about the data that's involved in figuring out pavement performance, whether the pavement is good, whether it's fair, whether it's poor, and where we're going and where the investment needs to be made to try to stretch that pavement life as long as possible. And it seems really appropriate to talk to him right now because a lot of his research and that of his colleagues will be used to inform some discussions and events next week in the state's capital.
Speaker 1:So I hope you enjoy the conversation, tim Lemon, welcome back to the podcast from pavement and how you do your forecasts and how you do the measures and all those things, and especially this week, because we're getting ahead of what should be a very interesting week next week with a big rally planned at the Capitol in Lansing with a lot of advocates for road funding, laborers, operating engineers, contractors all coming together to make their case to lawmakers and then the following day, a panel discussion, which all legislators have been invited to, by a number of people involved in the road funding debate, and a lot of that panel will be informed by the kind of research that you and your colleagues do. So thanks for being here and let's start off right away discussing pavement condition and how do you make this understandable for people? Because you know the average driver doesn't think in terms of what is good, fair or poor. So how do we relate people to? You know pavement condition in Michigan.
Speaker 2:Yeah, absolutely, jeff. Thanks for having me. I'm always happy to talk about this important infrastructure. You know, in terms of making pavement condition relatable to the public, I feel as though you know the public may not always have a solid understanding of you know the performance measures that we use, or the. You know the way that we actively manage our assets here at the DOT and even the way that assets are managed by other agencies. But what they do understand is when they drive down a poor pavement and they know it's poor, right, they see it firsthand. They experience the potholes and the cracks and the. You know the ride quality and all of that adds up to the things that we're actively using to understand the pavement's condition.
Speaker 2:So what we actually do internally to preempt those situations is we use a remaining service life measure that basically counts down the number of years until we feel the public would experience that poor pavement situation. Right, they would drive over and say, yeah, this is an estate where it's no longer meeting the needs of the public. So we use that as a budgeting tool, right, like, basically, we have a time until we know the pavement is ready for significant investment. There might be periods of time ahead of that investment where preservation type work could be applied that would extend the life of that pavement before we need to either take on a major action such as a rehabilitation or complete reconstruction, and so that preservation action really saves us a lot of money in the long run if we're able to hit that specific window before that remaining service life runs out. So the remaining service life, not only is it a condition and planning tool, it's also this budgetary information system that we can use to know exactly how much and when we're going to need additional investment.
Speaker 1:So asset management sounds about as geeky you know engineering as any term we use but it's probably one of the most important concepts to understand. And I've come to understand, you know, having done this job for a while now that MDOT has become a national leader, has been a national leader in that and that's you know. Necessity is the mother of invention, right, like if you're constantly underfunded, you've got to figure out a way to stretch the dollars, sometimes, I think, to our own detriment, you know, victim of your own success, right, because you managed to make it go so far and avoid a really catastrophic cliff. But talk about that in the context of. I mean, how would you explain it to any old citizen that you talk to about what asset management means and how your work factors in to the Transportation Asset Management Council's decisions?
Speaker 2:Absolutely. So you know transportation asset management. Funnily enough, I just got finished with the 15th National Conference on Transportation Asset Management here in Chicago, and what I'll tell you is that the principle really is pretty simple. You know, you have all of these transportation assets that are foundationally responsible for the networks that we use every day to get where we need to go, and so the question becomes okay, you have built all this infrastructure that we rely on as a society, so what are we going to do to ensure that it remains usable and that it meets the needs of the public? And so there's ways to do that that are more cost-effective, cost savings and more forward thinking in terms of the types of projects and modes that we put out there for the public to use.
Speaker 2:So, ultimately, you know, transportation asset management is a practice. It's, like you said, very geeky, right? There's lots of math and engineering involved, but certainly the principle is fairly simple. What you know at its core how do we provide this transportation infrastructure at the lowest cost to the public? And so we use a lot of math and optimization to basically plan out our investments such that we can do so efficiently and effectively.
Speaker 1:But it's kind of counterintuitive that a lot of agencies, I think, have been slow to adopt and catch on to this concept because worst first seems like the most logical way to approach the system, doesn't it?
Speaker 2:Well, yeah, certainly if you're the one using it. Absolutely, it seems the most logical when the road's bad, go to those locations and fix them, certainly. But, as I mentioned before, that remaining service life measure allows us to identify opportunities that we can prevent the road from becoming bad in the first place and, as it turns out, if you're able to do that, you end up saving yourself public funds to the next power magnitude 10 times as much funds, I think. In Michigan we spend, you know, if we're able to chip, seal or surface seal a pavement before we have to rehabilitate or reconstruction, those activities are, you know, maybe $100,000 a mile, $200,000 a mile If we were to reconstruct that same pavement. Oftentimes we're looking at more like $3 million a mile. So at the end of the day, if we're able to add that life extension before it falls into poor, before we're forced to apply those heavier fixes, we save everybody, you know the state of Michigan itself money overall. So that's really that core of that asset management planning that uses state funds effectively.
Speaker 1:Yeah, that's very well said and I know you've talked about this before on the podcast, but there are some debates, I guess, within this field, about the best measures for pavement, and RSL seems like a very scientific way to do it. Can you talk about that versus other measures?
Speaker 2:Absolutely yeah. So RSL is kind of a unique one in that it's a blend of hard mathematics and engineering judgment in the field. But we also have established what we call an auto logic, this automated system that can look at the pavement conditions, the pavement's history and the treatments that have been performed, to assign a remaining service life to the pavement, to say, okay, based upon all the data that we've collected about the way that the pavement performs and then deteriorates over time, we think that this is how long, realistically, this pavement section has. But obviously one size doesn't fit all right.
Speaker 2:If you've got a new, brand new asphalt pavement down in Detroit and you want to compare that against a brand new asphalt pavement, you know, say, up in Superior, it's very likely that those pavements will perform, you know, considerably differently. So what we do is we rely upon our regional pavement management engineers that are experts in their field you know, have spent a lot of time studying this to be able to understand the forces at work that deteriorate pavement and they inform that model, they provide their own input to once that forecast has been performed at the section level. Okay, I'm going to go look at this pavement. I I'm going to evaluate the drainage properties. I'm going to evaluate the traffic and, you know, maybe more specifically the truck traffic to have a better understanding of how is this really going to deteriorate and how much life can we realistically expect, you know, and maybe adjust that Autologic recommended service life.
Speaker 1:Stay with us. We'll have more on the other side of this important message.
Speaker 3:Avoid the wait and remember the Mackinac Bridge is closed to traffic Labor Day for the annual bridge walk, starting at 6 30 am. Spend some extra time in the UP or take your time heading north, since the bridge won't reopen to traffic until noon to allow walkers to clear the bridge. For more information, head to mackinawbridgeorg slash walk.
Speaker 1:So talk again about the traffic volumes that we're talking about on the high-level system, what we call the state trunk lines, the interstates, the M routes, the US routes that MDOT's responsible for, and why it's so important to commuters and really all of us and everything we do every day, not to mention the movement of goods, to keep that pavement in as good a condition as possible.
Speaker 2:Absolutely. And you know I work very closely with Mike Hecker from our pavement management area and he likes to say you know, all pavement's important right, all these systems are being used to. You know, whether it's a freeway downtown or it's the road to somebody's house, they're all being used by the public to meet their transportation needs. What I will say about the trunk line versus the local side is that they're really fundamentally different networks. The trunk line is about only 8% of our pavement network but it carries 50% of the passenger traffic and up to 70% of the annual truck traffic. So really you can think of that core 8% of the trunk line as being the foundation for interstate and intrastate mobility in Michigan.
Speaker 2:How are you going to get from Grand Rapids to Detroit? How are you going to get from Detroit to Toledo, whereas on the local side they may carry less traffic but they have a lot more pavement to cover. They've got many, many more miles than we do, obviously that other 92% and so fundamentally the needs of those two networks are different. We on the trunkline side we need really robust fixes to make sure that our designs stand up to. You know, tons and tons and tons of truck traffic going on, you know, every day battering those pavements, whereas on the local side they need to be able to cover more ground right. Maybe their fixes don't need to withstand the same level of magnitude, but certainly they have much, much more to cover.
Speaker 1:So you've taken a look at various funding scenarios like if we put in this much, we could get to this overall measure of good and fair, setting aside whether it's really accurate to combine those two categories or whether we should talk about them separately. What do you hear from your colleagues in other states about their goals for pavement performance? Sure?
Speaker 2:Yeah, so certainly they like to keep high goals and meet them. Typically I was just speaking with Ohio, not Ohio, the payment management expert from Ohio here at the National TAM Conference desire to rethink their aspirational goals for their non-freeway pavements and really what they were getting down to is maybe, instead of adjusting the goal, what we need to do is find a cheaper way to maintain those over time. And so he really he spoke to me about basically different practices in the way that we use surface ceiling, which MDOT is a leader in, ceiling, which MDOT is a leader in, and we kind of discussed, you know, the practices that he could use to reduce the overall cost of maintaining those non-freeway networks through the use of preventative maintenance, as I've just described today, and keep those goals high and keep the performance of the system high while reducing the cost to the public. So he's seeking out actually to do exactly what we're already doing here in Michigan, but you know he has the funding available to consistently meet the goals established by his legislature.
Speaker 1:Yeah, that's well said too. So talk a little bit about the challenges going forward. I mean, so talk a little bit about the challenges going forward. I mean our payment goals, as you know, are aspirational. What is your forecast? What's your number crunching? Tell you about what we need to get there versus maybe some lower but reasonable in terms of expectations levels.
Speaker 2:Yeah, that's a good question, Jeff, because that's been a hot topic in the field right now. You know, from the way that I see it, with rebuilding Michigan doing what it did for us, which is to take a lot of key locations, typically freeway sections, and bring them up into good condition from poor. Where we're standing now is that we have a buildup of fair pavements on the non-freeway. More than 50% of our non-freeway pavements are in fair condition and they're at risk of, based upon their remaining surface life within the next five to seven years, falling into that poor condition very, very quickly. So what happens if that big chunk of majority fair pavements all fall into poor condition at once?
Speaker 2:Well, the climb back up to even get back to where we are now is no longer, say, a 10-year prospect. We start talking about 15, 20, 30-year strategies at that time which, as you might imagine, you know from a from a funding standpoint is really pretty unsustainable. So it's better, as I've described, to prevent the network from falling into that disrepair by seizing the opportunity that we have now to take those fair pavements and make them good, good right, using preventative maintenance, using all the tools that we have in our asset management toolbox to prevent that catastrophic situation. So, realistically, I think it comes down to, you know, that RBMP, that Rebuilding Michigan program, really helped us save money and invest wisely in key reconstruction locations. But now it's time as a state to focus on that holistic asset management approach that we need to ensure the continuing infrastructure.
Speaker 1:Yeah, and I think it's really important to point out here that the decision to do Rebuilding Michigan and that involves bonding, which obviously involves debt was based on the failure to get any movement by the policymakers, any consensus on doing something sustainable. But we did it At the time it made sense, based on interest rates. I still submit that the debt incurred by fixing these roads pales in comparison to the debt that you would heap on your posterity by leaving them, these roads and bridges that are completely falling apart, and saying you know, not my problem, you guys figure it out. So that is expiring, as you said, and there's going to be some tough decisions If there's not enough funding going forward. We're still hopeful as the negotiations go on.
Speaker 1:That's what next week's events are all about trying to make the case. We'll see where we end up, but we know it's going to be a challenge. It's going to be an ongoing challenge. I don't know. You managed to keep a pretty good perspective knowing all these things. I certainly admire you for that. How do you do that? Thanks, jeff, I certainly admire you for that.
Speaker 2:How do you do that? Thanks, Jeff. Yeah, I mean I have optimism that the decision-making processes that be recognize the fundamental need for transportation for the state of Michigan. Right, there's really no getting around making sure that people can get to the health care that they need every day, making sure that people can get to their jobs so that they can support the economy and, you know, get home so they can support their families at night. So, in my opinion, one way or another, I believe that we as a state will find a way to to support each and every person of the state through that.
Speaker 1:Yeah, that's well said, too Well, tim. Thank you you, as always, for talking about this. It'll be really interesting to see what comes to pass as they get to the budget deadline, and it seems to be closely linked with a Rhodes plan. In the end, we don't know if those two will end up being severed or if they will get some kind of consensus at the same time, but it'll be interesting to watch. Yeah, we can certainly hope, jeff. I'd like to thank you once more for tuning in to Talking Michigan Transportation. You can find show notes and more on Apple Podcasts or Buzzsprout. I also want to acknowledge the talented people who help make this a reality each week, starting with Randy Debler, who skillfully edits the audio, jesse Ball, who proofs the content, courtney Bates, who posts the podcast to various platforms, and Jackie Salinas, who transcribes the audio to make it accessible to all.