Claim: Climate Change will Make Roads Rougher

Arizona Snowfall 2013

Guest essay by Eric Worrall

According to a study by Arizona State University, global warming will accelerate deterioration of roads because the original asphalt won’t cope with the anticipated rapid temperature rise.

Study Says Climate Change Could Lead to Rougher Roads

By Don Jergler | September 28, 2017

A study by professors at Arizona State University shows that global warming could add billions of dollars to the nation’s transportation budget for pavement costs alone.

“Transportation infrastructure is built to last decades, but engineering protocols in the United States assume climate stationarity, which may result in accelerated degradation and, consequently, increased costs,” a study out from academics at ASU states.

According to the study, if the standard practice for material selection is not changed to adapt to rising average temperatures, it could add up to $21.8 billion to pavement costs by 2070 under the same moderate global warming scenarios that predict average global temperature increases of 1.8 C.

The standard practice for selecting materials to build roads is based on average temperatures from 1966 to 1995, which differs from averaged based on data studied from 1985 to 2014, according to Shane Underwood, an assistant professor of civil engineering at ASU and one of the authors of the study.

“That may not be applicable going forward,” Underwood said. “That’s largely a decision on expectations that the future will look at lot like the past. That uncertainty can lead to higher costs.”

Read more:

The abstract of the study;

Increased costs to US pavement infrastructure from future temperature rise

B. Shane Underwood, Zack Guido, Padmini Gudipudi & Yarden Feinberg

Roadway design aims to maximize functionality, safety, and longevity. The materials used for construction, however, are often selected on the assumption of a stationary climate. Anthropogenic climate change may therefore result in rapid infrastructure failure and, consequently, increased maintenance costs, particularly for paved roads where temperature is a key determinant for material selection. Here, we examine the economic costs of projected temperature changes on asphalt roads across the contiguous United States using an ensemble of 19 global climate models forced with RCP 4.5 and 8.5 scenarios. Over the past 20 years, stationary assumptions have resulted in incorrect material selection for 35% of 799 observed locations. With warming temperatures, maintaining the standard practice for material selection is estimated to add approximately US$13.6, US$19.0 and US$21.8 billion to pavement costs by 2010, 2040 and 2070 under RCP4.5, respectively, increasing to US$14.5, US$26.3 and US$35.8 for RCP8.5. These costs will disproportionately affect local municipalities that have fewer resources to mitigate impacts. Failing to update engineering standards of practice in light of climate change therefore significantly threatens pavement infrastructure in the United States.

Read more (paywalled):

I’m not questioning Professor Underwood’s expertise with civil engineering, his ability to calculate the impact on existing materials of given arbitrary temperature changes, but an assumption that materials will remain static in coming decades is highly questionable.

There is huge ongoing investment into improving the durability of road paving materials, and increasingly robotic means of laying roads. To assume these advances will not significantly reduce road maintenance costs, to assume unlikely worst case climate scenarios like RCP 8.5, in my opinion is alarmist and absurd.

155 thoughts on “Claim: Climate Change will Make Roads Rougher

    • Did these researchers think about the CRITICAL application of paving temperature?
      From Asphalt Magazine
      The central role of temperature in asphalt paving
      “When it comes to building an asphalt pavement, creating and then maintaining the product within the right temperature range is absolutely vital.
      The reason is nicely described by what some call the “goldilocks zone.” To retain its compaction properties between the asphalt plant and being laid on the road, the asphalt mix cannot be too hot or too cold. Its temperature has to be just right.
      “Temperature is the key,” said Jim Scherocman, a Cincinnati-based asphalt consultant with 54 years experience in the business. “It controls all aspects of paving: How long it will remain workable on the job site, and how much time you have to finish laying it down and compacting it?” He added that the thickness of each lift also matters. The thicker the layer, the longer it will retain its heat and remain compactable.
      Unfortunately, a number of factors affect the final laydown temperature of asphalt, and thus how well it lasts for years to come. Here is a look at them, plus other temperature considerations that “keep the heat” on asphalt paving contractors.”

      • From Wolf paving,
        “Asphalt in Hot Weather
        In the warm summer months, the sun and penetrating UV rays have the potential to cause asphalt fading and increase surface deterioration. Extremely hot days can cause small waves in the asphalt surface and create soft spots. It is very important to consider proper asphalt installation and again, ensure regular sealcoating to make sure your asphalt surface is protected from warm temperatures and solar radiation.
        Mother Nature can negatively affect any road surface, including asphalt pavement. But it is important to consider that by taking the time to properly care for and maintain your asphalt surface — with regular inspection, repair and sealcoating — you can prolong the life of your asphalt in even the harshest weather conditions.”

      • What happens if it gets colder?? If the temperature drops to 50F it is to cold to lay asphalt.
        Asphalt is produced at temperatures of 250 – 300F (150c) and generally reaches the paving site within 20F of initial temperature. It is then compacted hot and hardens as it cools. It is still considered fairly soft at 200F and fairly hard at 175F. Considering that the temperatures would really have to dramatically increase to warm the roadbed so the asphalt reached “Reasonably softness” it is unlikely. The real culprit to breaking down asphalt is Cold, Snow, Icy conditions. As the ice forms it Expands within the road matrix breaking the bonds the asphalt has.

      • The temperature at which asphalt is laid and compacted isn’t relevant, as it is a condition experienced just once, for few hours at most, in the typical 20-year lifetime of most asphaltic pavements. What the professor seems worried about is the effects over the entire lifetime of the pavement.
        But his worry seems highly overblown – given the extremely wide temperature range that most if not all asphalt pavements are exposed to – ranging from well into the 120+ deg F in summer down to well below freezing, even 40-50 degrees below zero in the northern states, a global climate change of 2 deg C or 3.5 deg F is clearly within the noise range.
        Also, all asphalt pavement designs are a combination of raw asphalt, from oil, along with various emulsifiers and other additives as well as various aggregate mixes that affect pavement life far more than the extremely minor effect of a 3 to 4 deg F average year long temperature increase.

    • Air temperature will always be MUCH cooler than the pavement surface,it is a silly paper,since it is direct SOLAR Radiation that greatly heats up the pavement,not air temperature.
      I have seen cloudy hot days keep the pavement temperature down.
      The Abstract of the paper says NOT A WORD ABOUT SOLAR RADIATION effects.

      • Yep- it’s a tunnel vision of what the future could be if worst-case AGW were real.
        It makes more sense to predict a degrading highway infrastructure based on fiscal hardship imposed by policies attempting to mitigate climate change. Roads have always been expensive to maintain, ask anyone who lives rurally and has a private lane. With policies the progressives want to enact, the bank will be broken and the western infrastructures will quickly fall into disrepair.

      • For a good bit of the country having solar heated roads clears them from snow and ice…only to allow it to freeze again at night.
        HAH! water effects and thermal heaving are the primary natural destroyers of roads. Heavy transports are the primary use cause of wear and tear. And as far as solar damage, there are sections of the original Route 66 just east of Barstow running along US 40. Doesn’t get much if any traffic so it doesn’t’ get much vehicular wear.

      • All paving will be affected by the freeze-thaw cycle more than any thing else.
        Even more so, disturbance of pavement by contractors and utility companies companies will affect roads in even worse ways.
        The effect of warming can be readily be countered by more frequent use of expansion joints (although these will not alleviate freeze-thaw problems),

      • Rascal,
        You are absolutely correct, while I am not a road construction expert I have a MS in Civil Engineering and it is well known that freeze thaw cycles cause much of the damage to asphalt roads. Water entering cracks and freezing/thawing cycles causes destruction of Asphalt roads.
        Besides if one looks at the temperature data for the USA it is clear that the claimed warming comes from higher low temperatures overnight and that heatwaves are less frequent than in the past.
        Are these folks ignorant of the facts and data or do they not care about integrity of their work, only get another grant?
        This nonsense has to stop.

      • If overnight freezing and daytime thawing are damaging to asphalt (they are) then “global warming” should help asphalt because warming predictors predict that most warming will come from increased nighttime temperatures. And if increased cloud cover is another result of GW, then the daytime pavement temperatures should trend lower, not higher. Oops, never mind.

      • Potholes don’t need freezing water. The water intrusion rinses out interstitial sediments which act to interlock the larger gravel and fractured pieces. As the vehicles continue to mechanically work the loosening rubble the water further erodes the interlocking grains and the hole begins as material is ejected by vehicular loads. The margins of the pothole will begin to erode at an accelerated pace as the mechanical damage is exacerbated by the growing defect.
        But, you are correct in that a good bit of road damage is cause by thermal heaving. It can start the cracks that allow water to penetrate.

      • Winter is the true killer of asphalt. The freeze thaw cycle breaks large chunks of asphalt free, while the contraction of the asphalt due to cold results in cracks (which are then victimized by the freeze thaw). Often salt is used to help reduce ice on the road surface, and that also plays havoc on the asphalt. Warmer weather climates have great roads that we Northerners marvel at.

    • If it gets cooler, it’s real, it’s us, it’s serious and it’s time to act now.
      If it gets warmer, it’s real, it’s us, it’s serious and it’s time to act now.
      If it remains the same, it’s real, it’s us, it’s serious and it’s time to act now.

    • The roughest roads (real major highways) that I have ever encountered in my life were up in the State of Alaska. After surviving on the loose gravel surface of the AlCan Highway (piece of cake), when I entered the State of Alaska and headed down the main road towards Anchorage, I found long stretches where I could not drive faster than 25 MPH because my car (VW Squareback sedan) became air borne if I tried to go faster. I destroyed a total of six brand new tires on those paved roads in Alaska. My jack broke on the very first puncture, so I had to dig holes in the road (shoulder) under the wheel to change wheels (yes I did have two spare wheels for that journey.)
      Perma-frost buckling, I think is what they call it. Concrete surfaces, that were completely undriveable.
      Couldn’t get a new jack till I got to the VW dealer in Anchorage. (July 1967 on a trip from St Charles MO, to San Jose CA.)

  1. According to the study, if the standard practice for material selection is not changed to adapt to rising average temperatures …

    It’s the Maximum temperature not the average that will cause degradation of material. Besides, it’s been pointed out many times on these pages that the average temperature is largely due to an increase in the Minimum temperatures.

    • It’s also the range of temperature that degrades the material, so that increasing nighttime minimums coupled with decreasing daytime maximums should improve the surface life.

      • Kudos to steve, jorge and paul… i was wondering how far i’d have to read into the comment section before some one(s) got it. “Y’all are on the ball”

    • If a road is built to tolerate swings of temperature of up to 20-30 degrees centigrade within 24 hours, how does a rise on average of 1-2 degrees over a hundred years (well beyond the maintenance free lifespan of any road surface) create a problem?

      • a totally absurd argument of those professors Arizona State University. They are showering themselves with bullshit.

      • We’re getting a swing in temperatures of almost 50F cooler in the space of 48 hours here in North Carolina. Guess I better go out and buy a horse because the roads aren’t going to survive!!!
        Isn’t it also common knowledge that potholes appear in the winter and spring because of ice expansion in the cracks in the asphalt? And throwing salt on the road accelerates that process.
        I am ashamed that the hysteria is now invading the engineering profession.
        “Mechanical Engineers build weapons. Civil Engineers build targets.”

      • More than “invading the engineering profession.”, it is the academics looking for grant money. This study is obviously stupid, but some guy got funding for 2 years of ‘study’.

  2. What will make roads rougher is under investment in building and repairing roads as funds are diverted to bureaucrats favorite “renewable” scam.
    James Bull

  3. “To assume these advances will not significantly reduce road maintenance costs, to assume unlikely worst case climate scenarios like RCP 8.5, in my opinion is alarmist and absurd.”
    Of course, you are correct. However, there isn’t much (grant) money or prestige to be had from saying, “Bit of a problem here, but nothing we can’t address with some forward thinking, leading to mild adaptive strategies.”

  4. If asphalt can’t stand 0.3 °C, how does it work with day/night temperatures?
    Crackpot study again… “Want more money!”

  5. RCP8.5 again? Besides, Tony Heller has gone on at great length that maximum temperatures in the US show a historic decline over the 20th Century.

    • … Tony Heller has gone on at great length that maximum temperatures in the US show a historic decline over the 20th Century.

      Tony will tell you that NOAA’s Climate at a Glance data is “Fake Data” but even so, it shows that there’s been a decline in Tmax in in the eastern United States, and most of those states show a decline May – October all the way to the 19th century.
      Here’s what that looks like:

    • “RCP8.5 again?”
      They always use the worst-case scenario.
      When was the last time the Earth entered into a “Runaway Greenhouse phase?

  6. These conclusions don’t pass the smell test. I’m not a civil engineer, but my observation is that in every part of the US that I’ve lived, asphalt roads don’t have a life expectancy of even 20 years. In that timeframe, under any scenario, I can’t see that there has been or would be enough air temperature (~0.01 C or less) change to have any real impact on road material selection–for practical purposes, the engineering assumption of static climate over that period is and will continue to be valid. If the authors think that there has been “mis-selection” of road materials over that time frame, it seems to me the only rational explanation is human error, not climate change.

    • Having lived in the Midwest, Great Plains, Texas and now the Southeast Coast, the roads are in much much better shape the farther south that you go (as long as the state isn’t dirt poor and actually maintains them as needed).
      The salt every winter and the melting and re-freezing of ice is what kills the roads. That’s why where I grew up (NW Indiana 50 miles east of Chicago), the roads were concrete and lasted much longer. We had potholes but they filled the same spots year after year with asphalt and they would never last.
      I still laugh at the time we lived in Madison, WI and during several major snow storms, the first thing they did was plow the bike paths. Because you know in such a progressive forward looking place, my first choice of transportation in December and January is my 12 speed.

  7. Most road degradation is in the winter due to water melting and refreezing. You don’t see many potholes in the summer. And asphalt’s biggest issue is overweight trucks. Residential streets in the south with no truck traffic actually can last decades without repaving.

    • Add to that the sand and salt spread over them when it snows, and the scraping of snow plows and truck chains. Winter temps and water/ice degrades roads faster than warm temps do. A civil engineer would know that.
      He should also know that the 1.8C calculated crap is a rise in “anomaly” temps, not absolute temps, and that a rise in the “average global temperature” does NOT mean the temp of the entire planet will rise that much. Not ALL roads would be affected even IF the prophecies are correct.

      • Aphan. Sad to see that global warming nonsense has moved from Marxist Sociology to Civil Engineering. This article is a shame and nonsense. Which party you vote for makes orders of magnitude more difference than a hypothetical rise of a degree or so.

    • In the Northeast, the damage done to the roads by freezing in the winter and subsequent melting in the spring is call “frost heaves”. We have some form of this damage every year because (gasp) it gets cold every winter! I don’t know how we can predict this annual occurrence of winter but somehow we do…

      • Don’t forget the occasional water main breaks which can wipe out the pavement and the road bed in minutes. Mostly seen in frigid weather.

  8. Another non-problem, simply use a different grade of asphalt or a different material next time the road is repaired – IF the climate ever gets too warm – it’s not as if a road has a significant lifespan. Different areas already do this to suit their climate.

  9. I realised that this was propaganda when I read the line: “The materials used for construction, however, are often selected on the assumption of a stationary climate.” Yeah, sure, within the “stationary” range of the area within which it is used. In Northern Ontario that range may be -30 to 30 C and the materials must remain viable within that range. If that is what they mean by stationary…OK.
    As noted by another commentator, materials are always evolving, as better solutions that increase the range are played with. I don’t thonk that will change.

  10. Most of the weather related damage to pavement I see is related to the freeze/thaw cycle causing potholes.

    • Yes, you beat me to it. But you just know that they would then find a way to claim that the freeze-thaw cycles would somehow become more damaging….
      Separately, when the person you are listening to uses the phrase “going forward”, you know you are dealing with a pseud.

      • Well that happens when an area that usually doesn’t get snow does get some and needs to remove it, but has no snow removal equipment. Such an occurrence happened in Southern Illinois in the 80’s. They conscripted all sorts of agricultural and earth moving equipment to assist in the snow removal. Not only did the roads suffer, but also the curbs and sidewalks too.

  11. More mindless BS. As I’ve said all along, “global” warming is driven by the increase in temp at the North Pole ……. there are NO roads across the Arctic Ocean, and even a “warming” Canada or Siberia is not going threaten any roads.

      • How much melting is due to human construction/habitation altering the area by adding heat absorbing structures and surfaces?

    • In the part of Canada that I am from, it is frost penetration of the roadbed, and consequent heaving, that causes the most damage to asphalt.

  12. Quick fix for that: Ban all petroleum drilling of any kind. That way there will be no asphalt. Idjits is as idjit does.

  13. What? Wyoming roads will deteriorate even faster with a few degrees of warming? Sorry but I’m calling Barbra Streisand on that. With a normal diurnal temperature range of 30-40°F the poor things have a hard time no matter the maximum and minimums now or in the future. And to think, as noted, that material science won’t have better building materials in the futures is also ridiculous. Now whether the advanced materials will be taken advantage of is a different story; cost being the main deterrent.

    • Thanks. I was going to note the same thing. Wyoming has massive temperature swings and the roads still more or less hold together. In Shirley Basin, at one time the road crew installed a “fabric” under the road that did seem to make the pavement last longer, longer being a relative term, of course. There are many ways to deal with road construction.

    • Interesting on the delineation of the development. One can almost see national boundaries….
      Why did the citizens decide to pave so much of North Dakota?

    • An interesting visual but useless drawing regarding UHI — line thickness relative to road width is distorted.

    • Thanks for that,
      Also think about the cost to duplicate the fueling stations required for all the roads if they mandate the ban on gasoline and diesel powered cars with electric vehicles, not to mention the cost of upgrading the grid and collecting fuel tax.
      The current fuel supply structure was provided by private capital investment over many decades and these Electric car advocates are either ignorant of the infrastructure required or they intentionally ignore the problem, expecting that taxpayers will subsidize the electric “filling” stations.
      I wonder why those smart people in the MSM fail to report this issue?

      • Also looking at the map and copying the URL, I note this is the daily mail which if I am correct is not a US publication.
        I wonder why the USA Papers do not seem to publish important information like this but only stuff that fits their agenda. I have noticed this on other mostly political items mostly those that embarrass the Democrats.

  14. The simple solution here is to stop all federal funding for roads in Arizona and other desert areas. That way there will be less damage to record, especially in southern Arizona.

    • You are correct. The number of Freeze / Thaw cycles a road experiences is an important indicator of how quickly it will deteriorate. If warming shifts the freeze line northward, more roads are spared that stress, so more roads should last longer.

    • Absolutely in the US Midwest !
      The worst is water getting in a cracks in the road, then freezing and expanding, enlarging cracks.
      All summer they are repairing the damage (potholes) from the winter damage.

  15. “I’m not questioning Professor Underwood’s expertise with civil engineering.”
    OK, so I won’t either. But let us consider the the prevailing climate regimes.
    Seasonal temperature range and day/night temperate range are much greater than the long-term changes that IPCC claims we might expect even under the 8.5 scenario. Nothing to worry about there.
    The diurnal range has changed: night-time temperatures tend to be slightly higher while daytime temperature maximums have not changed much. So the diurnal range is slightly less now than before.
    So if temperature range is not a threat, the process that damages road must not be temperature range, but extremes of temperature.
    And there is the flaw in the argument. America is a big place and the states at most risk from extreme temperatures are most at risk but not from change in climate. Rather extreme heat in the early afternoon has always posed a threat to asphalt roads.
    And extreme cold has always posed a threat to all types of roads. But nobody is saying that extreme cold will be a problem in the future, only extreme heat.
    Climate also includes rainfall and extremely high rainfall poses a threat to all types of roads. However, we don’t hear much from the IPCC about extreme rainfall because there is so little evidence that extreme rainfall events are increasing.
    So what problems can we expect for roads: lack of maintenance and insufficient investment to keep up with increasing traffic volumes and loads.
    For roads, the elephant in the room is maintenance, including the maintenance of road drainage systems.
    The elephant’s sister is: design standards of existing roads were lower in the past than now. Now axle weights may be higher and traffic volumes may be higher too.
    As a result, some roads may not have been designed to withstand current levels of wear and tear. The economic life of some roads will be less than their design life.
    How would the professor be able disentangle the traffic variables from the climate variables? Is it possible to smell a rose in a windstorm?
    That seems to me the most interesting part of the paper.

    • Arizona and parts of California routinely hit 120°F, yet somehow their roads manage. I did have a relative who melted the bottoms of his NIke’s standing on hot asphalt in Arizona, but that was it. I’ve driven on the roads when it was well above 100°F in many states. Not a problem. More problem with black ice.

    • Paving the desert landscape with asphalt roads and parking lots is a much greater impact than any general climate change impact, real or advocacy driven.

    • Yet more disingenuous tripe from the mendacious little bedwetter trying to promote his false religion for his paymasters..
      That has been happening to my certain knowledge since the 1960s, Skanky.
      In 1976 the gritters were out almost daily due to the melting tarmac.
      But the fact remains that the weather condition that damages the roads is frost.

  16. I’ve always found winter is the biggest destroyer of roads, what with the freezing and thawing. I was going to say just like El Capitan, but there’s a different process at work there. But certainly like other rocky peaks in the mountains.

    • It’s the same process at work in El Capitan. Water works into the cracks and then freezes.
      I don’t believe it is a coincidence that both collapses occurred in the area that is wet by a spring time water fall.

  17. Holy crap…..I cant take it, stop it with this discussions. This statement of the roads in relation to “climate change” is officially one of the most ridiculous things ever said.
    On another note; Is it true that global sea surface temps at the moment are only 0.20C above the 30 year avg (71-2000)???? If someone could please answer that for me, I just want to confirm.

  18. He acts like you can’t move different materials around…..and all roads are made the same
    ..if it does get warmer, just start making roads in Maine with the same materials and same way they are made in Florida now

    • With the type of climate change they are talking about, its more like making the roads in Maine with the same materials they are currently using in Connecticut. We are only taking about a few degrees difference. IN most cases, it would not be enough to change methods or materials.

  19. “… to assume unlikely worst case climate scenarios like RCP 8.5, in my opinion is alarmist and absurd.” Well said Eric!
    What really wrecks roads and buildings, is when the temperatures go from very cold winters to warm/hot summers. Mix that with some water ingress from rainy/snowy periods, and mortar will move with bricks and concrete slabs, window frames, roofing shingles/tiles all loosening, also roads will tend to crumble quicker. As one who has survived the climate for more than half a century I have seen and had to repair/maintain such problems over the decades.

  20. On Wednesday, I wore a sleeveless t-shirt because it was hot. A cold front came through Wednesday night, and yesterday, I wore a long sleeve t-shirt. It worked out great! It did not take me 100 years to decide to put on a warmer shirt. It didn’t take any effort or planning or a scientific study from a major university. There was no crisis or catastrophe. It didn’t cost me any more money. The weather got almost 20 degrees cooler and I put on a long sleeve shirt. Just like that! It’s called adaptability, and we humans have it in abundance!
    Why would anyone be worried about a 1 or 2 degree change over 100 years? An amoeba would take such a change in stride. Are road engineers dumber than an amoeba? Of course not! Those who write about the horrors of climate change however, …

  21. Asphalt cement concrete highways have a useful design life of about 30 years. Mix design is an old field of civil engineering and new methods of mixing and choosing additives to increase the life or wear and temperature resistance are being developed all the time. If, over the life time of a highway surface, there is measurable change in the ambient temperatures, the next surface will have this information available for the design engineer. Road bed design is far more important to the longevity of the surface and is very consistent through a very wide range of temperatures.
    I didn’t see the bio’s of these authors but must question their knowledge of highway materials and design or their intent in doing this study.

  22. I live in upstate New York, where the roads of whatever material – asphalt, concrete, gravel – suffer due to the pounding of snowplows and the freeze/thaw cycles. I was hoping global warming would help us. What a disappointment that it seems not to be working. /sarc

  23. Although the warmlist is no longer being added to since 2015, it is still worthwhile looking at if only to point out the ludicrous and insane nature of global warming alarmism. These people are truly suffering a form of insanity, or maybe so many just want to get in on the scam.

    • People live in times when conformity is 100% mandatory and punishment is handed out if one dares cross the established norms. When you live under constant duress to be what the government and press demand you be, people often say whatever it takes. It’s a result of social media and the breakdown of society. All there is for support are the peer groups. You go along or you go alone.

  24. Most roads in London are more than rough, in fact many are more akin to a lunar surface.
    It has nothing to do with temperature, it’s cheap materials and a lack of maintenance.
    Keeps the costs down you see….

  25. Just another study spinning what is a positive, into a negative. Freeze thaw cycle does the most damage. Global warming increases minimums the most and decreases the diurnal temperature spread(slightly) as well as increases temperatures the most in the coldest places in the coldest times of year.
    Warmer Winters will require the use of LESS harsh chemicals on roadways, needed to lower the freezing point of water.
    From their study:
    “Kentucky tops the list with the highest median increase at $26,127 per mile per lane”
    The other thing. When the air temperature is 100, asphalt, at peak sun can get up to over 160 degrees(others might know the exact number)……….because of the peak sun.
    If we assume that the suns angle and power will remain the same and add 60 degrees to the temperature of the asphalt, even a jump of 4 deg. F(which is pretty far fetched in my lukewarmer world) means the asphalt will potentially get up to 164 deg. F.
    In the state of Kentucky, for instance, we are to believe that asphalt is going to degrade so badly on the extraordinarily rare occasions that it peaks at 164 degrees vs the previous peak of 160 deg. F that the cost will average $26,127 per mile per lane?
    And the fact is that daytime temperatures in the Summer are not increasing in the US. The 1930’s were still the hottest………by a wide margin for daytime max’s and heat waves.
    The potential increase in the temperature of asphalt would peak around June 21st, with the peak in the sun’s angle………which is the biggest determinant in raising the temperature.
    Seasonally, with the lag in the air temperature, the peak in the hottest days is usually 30 days after the peak intensity from the sun.
    On July 21st for instance, the air temperature can be 104 deg F. but the asphalt temperature may be lower than on June 21th, with an air temperature of 100 degrees.
    On August 21st, on a sunny day, you can have the hottest air temperature ever recorded for that location but the asphalt will be far shy of the hottest.
    The sun’s position in the sky on clear days is the biggest determinant of asphalt temperature.
    Studies like this, that can be obliterated on many levels by somebody that knows very little about asphalt using some common sense, basic meteorology knowledge, expose the objective………..find evidence, even if it’s manufactured of major, costly consequences of human caused climate change.

  26. Ice-melting salt prevents road surfaces from expanding in the freeze cycle. Wherever there is a break in the pavement, salt prevents freezing expansion, ergo “THE BUMP” ERGO “THE HYDRAULIC RAm,” ERGO “the wasteland”….

  27. The standard practice for selecting materials to build roads is based on average temperatures from 1966 to 1995

    I thought one takes the most extreme conditions recorded and then design for 50% above that.

  28. Interesting…ASU and this group of engineers is also working on designing new formulations and additives to increase the longevity of asphalt concrete. Nothing makes a sales pitch more solid than pointing out that a “new” product is better than an “old” one because it might save you billions of dollars in the future…
    Is it a conflict of interest to produce studies that might be used to earn money in the future?

  29. …I’m not questioning Professor Underwood’s expertise with civil engineering, his ability to calculate the impact on existing materials of given arbitrary temperature changes, but an assumption that materials will remain static in coming decades is highly questionable….
    Nonsense!! Here in England we expect a lot of problems with getting mediaeval ox-carts over Roman cobbled streets. Because that’s what we’ll end up with if the Greens have their way…

  30. There is actual road maintenance cost data available to help answer the professor’s concerns – no need for climate models. See Nice hot South Carolina has the lowest cost per mile while nice cold Maine ranks just below it at 5th (out of 50 States). There doesn’t seem to be an average-temperature effect there. Someone with better computer skills than I could plot State cost rankings versus State average temperature to see if there is a trend, but my eyeball says no.

  31. This paper does help prove one thing, that academics are willing to sacrifice all ethical behaviour to get a few grant bucks from this scam

  32. Somewhere out there is a netbot spewing out articles daily with a title:
    “Climate change will make [noun] [comparative adjective]”
    Climate change is already making dumb dumber.

  33. this is the straw that broke this camels back, i try to have respect for people with degrees but no longer CAN, simply because they are LIARS as a group…….simple grade school science shows their claims about humans causing global warming are IDIOCY in the extreme….even the few that dispute them still say well humans do have an impact, which again on a global scale it total BS…..

  34. “scenarios like RCP 8.5, in my opinion is alarmist and absurd.”
    These RCP scenarios are yet another level of obfuscation increasing the separation between the faulty claims and the physical laws that quantifies how incredibly wrong those claims are. Currently, there are at least 4 levels of obfuscation between the controlling physics and the presumed effect and that they keep adding more uncertainty and wiggle room tells me that they know, or at least suspect, how wrong they are.
    All they did was add to the +/- 50% uncertainty in the sensitivity with even more uncertainty in what the forcing will be while still assuming an absurdly high mean climate sensitivity. Adding all the uncertainties, the nominal effect from the RCP8.5 scenario has an accumulated uncertainty/error of more than +/- 100%, thus no change at all is within the range of possibilities.
    Anyone who claims that science with this much uncertainty is settled is either a fool, has absolutely no understanding of how science works or is a stooge for the IPCC and/or the political left.

  35. Not to disagree that frost and cold are harder on pavement than heat, but heat can cause blowups in the asphalt, when the asphalt expands upward. My father worked for the highway department and was always going out to repair these blowups. It was in the 1960’s when my father worked there. It’s not new in any way nor an indicator that the world is warming.

  36. I have driven in nearly all continental US states, quite a bit with a trailer, and some of S Canada and N Mexico. I would bet temperature (cold as noted above) is the second most important factor. You could easily guess the first. Old recollections, but Arizona roads were better than Nova Scotia, not the latter’s fault.

  37. I have always found the worst roads are in cold areas. Cold cities need to constantly repair roads because of damage from snow ice and salt. Warm areas get away with not fixing roads for years.
    Another one for the dubious studies department.

  38. Another vague nebulous study based on gross assumptions, a claimed “moderate” scenario and a tremendous amount of confirmation bias.
    The authors’ solely focus on an asphalt road’s maximum temperatures during a year.
    •* No explanation regarding how CO2 raises ground temperatures.
    •* Zero research effort into why local, state and Federal governments choose certain grades of asphalt. •* Somehow, I doubt the majority of asphalt decisions are made based on a maximum estimated asphalt temperature during a very brief period of summer with maximum sunlight, that temperature is achieved. I’ll lay odds that cost of the material and cost of effort to apply that asphalt are primary drivers.
    •* The author’s assume other studies into asphalt cracking and failure rates are caused by “climate change” and “maximum asphalt temperature”. Extremely odd, since every Northern state that I’ve lived in blamed a majority of asphalt failures on one or more of three things;
    •* •* a) road usage by heavy traffic (weight of vehicles),
    •* •* b) freeze/thaw cycles,
    •* •* c) degree and depth of proper road subsurface preparation.
    Fire the lot of them and demand any grant monies refunded.

  39. I’m not questioning Professor Underwood’s expertise with civil engineering, his ability to calculate the impact on existing materials of given arbitrary temperature changes…

    Well, I do. Looks to me to be just another ivory tower Ph.D. jumping onto the CAGW gravy train to get a paper published and fluff up his CV. I very much doubt he’s a practicing CE who has actually specified and overseen road construction projects. I know several excellent CE’s who would tell you that this paper is nonsense and an insult to their competence.

    • I don’t design roads in Arizona or Alaska (or any extreme temp area). I don’t give a crap about climate (existing, past of future) in road design. The temp range where I build roads is between 10 degrees and 115 degrees (Fahrenheit).
      As stated by numerous people above, almost all of the damage/deterioration is associated with the cold (or with drainage problems; subgrade moisture changes).
      Roads are “designed” to last 20 to 30 years; my local/collector roads have been in place about this time frame and by all appearances will be in good condition for another 20 years. (“My portion” of state highway is about 15 years old … not yet old enough to use for evaluation.) Even the roads I cheaped, and took a chance on, will double the design life. Minor increase in temp over the design life of a paving structure aren’t going to make any difference….
      The private asphalt industry does, and will, spend a lot of time & money on research/evaluation of paving needs; and they don’t need this type of a study to help them.

    • I don’t do any work in Alaska or Arizona. The max temperature range where I do work is somewhere between 0 and 110 degrees (Fahrenheit). Given the lack of significant extremes, I don’t give a crap about temperature (average, high, or low) with respect to asphalt mix in my road design.
      Typical road design is for 20-30 years. My oldest roads (local/collector) are about that age and appear that they will last another 20 years without any significant maintenance. “My ” section of state highway is about 15 years old now and it is also appearing that it will meet or beat its 30 year design life.
      This study states that pavement designs should have differed in 35% of his 800 observed locations because of the stationary climate assumption of the designer. Jeez, maybe I shouldn’t admit it, but I made absolutely no assumptions about changing (or stationary) temperatures over the design life of my roads. I wonder if he would be interested in notifying those 280 engineers that, in his opinion, they screwed up.
      As others above pointed out the cold is the primary parameter associated with paving degradation. They are all correct; cold, and poor drainage leading to subgrade failures, are the main problems. So, the benefit of any low end warming would vastly outweigh any cost associated differing ac mixes. If the author of the paper really cared about providing honest information he would have included this somewhere.

  40. As we’re all due to be driving (or will Big Brother be driving) shiny lovely new electric cars, why not just make the wheels bigger?
    That’ll give a smoother ride.
    Or let some air out of the tyres…
    Use tyres like ATV quad bikes have…
    Eat huge amounts of pizza (or any other carb) to develop a massive fat arse, in exact inverse proportion to what the pizza does to your brain, and get a smoother ride that way.
    What is wrong with these people?
    Oh look, they’ve gone down to Pizza Hut………………

  41. They are right that climate change has made the roads rougher here. The frost last winter has made them more like obstacle courses than thoroughfares. It certainly has changed from the predicted Mediterranean climate the climate scientists predicted when they still called it global warming.

  42. The key words in the abstract is “anthropogenic warming”. Planet warming and cooling have a place but minuscule temperature changes as a result of human activities seem somewhat displaced.

  43. You know what makes roads rougher? Lack of maintenance – Oregon has done a wonderful job of letting everything go ruin – sort of a backwards way of getting people out of their cars. Nothing there to replace the roads, but at least the Progressives fuel their warm-fuzzy buzz by yet another act of destruction – albeit a passive/aggressive approach.
    Oregon IS, however, still spending it’s transportation budget – and a LOT of grants from the Feds – on billion-dollar ‘green’ projects – such as our gold-plated ‘MAX’ train which carries approximately 3% of the population (north and south only, but they do have bike racks on the front of the train). They also had a pretty good grift going on ‘researching’ our Interstate bridge project – promising to put the train across the river – again sucking up all those federal dollars.
    I don’t remember the exact math, but pretty much every single car on the MAX would pay for a fleet of busses.
    Oh yeah – the train doesn’t work if it’s too hot or too cold.

  44. The temperature at which asphalt is laid and compacted isn’t relevant, as it is a condition experienced just once, for few hours at most, in the typical 20-year lifetime of most asphaltic pavements. What the professor seems worried about is the effects over the entire lifetime of the pavement.
    But his worry seems highly overblown – given the extremely wide temperature range that most if not all asphalt pavements are exposed to – ranging from well into the 120+ deg F in summer down to well below freezing, even 40-50 degrees below zero in the northern states, a global climate change of 2 deg C or 3.5 deg F is clearly within the noise range.
    Also, all asphalt pavement designs are a combination of raw asphalt, from oil, along with various emulsifiers and other additives as well as various aggregate mixes that affect pavement life far more than the extremely minor effect of a 3 to 4 deg F average year long temperature increase.

  45. It’s easy to test this hypothesis. If it is true, roads that run north-south would have significantly higher road maintenance costs 50 miles further south of a point than 50 miles further north of a point.
    I don’t believe this is true. However, if they have the data that actually shows that, I’d be open to it. From what I do know, more freezing cycles causes more road damage.
    In the southern US, fire ants are a major cause of damage to roads, undermining the bed, but his solution would not affect that.

  46. I am really concerned how the Solar Panels, Wind Turbines and Elon’s Batteries will handle this extra heat??

  47. If I could just have my flying car, as I was promised by the wise futurists of the 1960s, I wouldn’t give a damn.

  48. In the north, the big issue is the number of freeze thaw cycles. Guess what happens when you don’t go below freezing as often?
    I don’t even need a PhD to know what will happen.

  49. After reading through the comments to date i havent seen an actual explanation of how hot mix asphalt design works. Aside from the aggregate component, the binder or Asphalt Cement is selected for the geographic area based on the local temperature. For example, in many parts of the midwest US the main binder is PG 64-22. The 64 stands for the maximum 7 day average pavement temperature, the -22 stands for the minimum 1 day pavement temperature ( both in degrees C ). So even if over the next 100 years there is a 2C rise, the PG grade would just be adjusted if the job temperature changes to say PG 70-22. The grades are in 6 degree C increments. Also, most Hot Mix Asphalt pavements are designed for 15-20 years max and most require some sort of rehab during that time for a variety of reasons. The aging of the Asphalt Cement is a major contributor to the pavement failure, other than reasons others have listed, heavy trucks, snow plows, freeze-thaw cycling,etc.

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