Rain has more consequences than just delaying the race.  Track drying is really hard on the surface.  Most materials expand when they heat. (Water is a notable exception).  Asphalt is a mix of different types of rocks held together by an asphalt binder.  When you heat the asphalt with a track dryer, you are putting a lot of heat into the track.  Different materials expand at different rates, and the amount of heat that reaches the inner layers of track is different than the amount on the surface.  The rapid change in temperature creates a lot of stress in the asphalt.  Track surfaces, like people, tend to crack when under stress.

There are already a lot of cracks in the Daytona surface that are covered by sealer and other fixes (like epoxy).  Sealers also expand and contract at different rates, so thoses are high priority places to watch for new problems.  Given the age of the track, it is entirely possible that there are areas that are weak or cracked just under the surface that might be pushed to the brink with a little thermal cycling.  (Thermal cycling being repeated heating and warming.)  The Daytona track folks will walk the track, but all they can see is the surface.  Keep your fingers crossed not only that we don’t have rain delaying or canceling the race, but that we don’t have rain period!  I don’t envy the track personnel today – they are going to be really happy when the track reconstruction starts.

Take a look at my earlier post on the Daytona issue.

Questions:  email diandra(at)buildingspeed.org.  Will try to answer during the race, but there’s a possibility that I’m going to be at Best Buy asking them to “demonstrate” their 3D TV’s!

Last week at Texas Motor Speedway was not fun because of the rain. There were short periods of downpour and then just moisture hanging in the air that would not go away.

But we didn’t have to deal with severe storms and tornadoes. Having spent 14 years in Nebraska and 16 in Wisconsin, I am more familiar with tornadoes than I would like to be. The words that are most worrisome in the forecast are “tornado outbreak”. If you have a short attention span, scroll down to the last section of the article, which tells you what you should be doing if you are out at the track or planning on coming out.

Tornadoes are a primarily North American phenomenon, with the U.S. having about four times as many tornadoes as all of Europe (excluding waterspouts and if you ever lived in Nebraska, you know why). North America stretches a long way North to South and there aren’t any major east-west mountain ranges that block the flow of air all the way from Canada to Mexico, so much larger fronts can form than in areas with more mountainous regions.

The Midwest has a lot of tornadoes — as you can see from the figure at right — because the Rockies block moisture and cause the atmospheric flow to buckle, forming low-pressure, dry areas to the east of the mountains. The Gulf of Mexico is a great provider of moisture, which makes for ideal conditions for tornado formation. The U.S. averages about 1,200 tornadoes per year. Most happen between 3 p.m. and 7 p.m., but they can occur at any time of the day.

The worrisome thing this weekend is the prediction of a tornado outbreak, but let’s look at one tornado at a time.

Tornadoes form in boundary areas, like those between hot, dry air in the West and warm, moist air in the East. The Central Plains states, like Nebraska, frequently experience strong storms this time of year. Those storms move East and, depending on their North/South extent, can cause storms and tornadoes throughout a wide swatch of the country.

The worst tornadoes are spawned by thunderstorms called supercells, which contain mesocyclones. ‘Meso’ means ‘mid’, so a mesocyclone is a medium-sized rotating air mass and, in meteorological terms, that means from a mile to five miles across. Supercells also have very heavy rain, lots of lightening, strong winds and hail.

When it starts raining really hard, the rainfalll drags air down with it toward the back of the supercell. The downdraft accelerates as it nears the ground, and drags the supercell’s mesocyclone down with it. If you see a cloud that shows any sign of rotation, that’s time to start being concerned. The mesocyclone approachs the ground, and a condensation funnel forms. The condensation in the storm is the same thing as steam forming water droplets on the lid of a pot of boiling water. The coolness of the downdraft condenses water from the air, and that forms the condensation funnel. The rear downdraft keeps moving downward, which creates a very strong wind capable of causing damage well away from the funnel cloud. A funnel is a rotating structure descending from the clouds, while a tornado is a funnel that has reached the ground. The funnel cloud can become a full-fledged tornado within minutes of the rear wind gust hitting the ground.

Tornadoes are powered by warm, moist air. The more air, the more energy the tornado has, and the tornado will keep growing as long as it has access to warm, moist air. Tornadoes with diameters of more than a mile have been reported. At some point, the cool rear downdraft will wrap around the tornado and prevent more warm air from reaching it. The vortex, deprived of energy, begins to weaken, the size decreases and the tornado can be dispersed by the straight-line winds from the storm. Don’t let the size of a tornado fool you. Even what appears to be a small tornado is capable of causing a lot of destruction due to conservation of angular momentum. When an ice skater is spinning, she spins more slowly when her arms are out, creating a larger effective diameter. When she pulls her arms in, she spins faster. A thin tornado can still feature very strong winds.

Once the original tornado is gone, it’s entirely possible for the cycle to repeat again, with a new mesocyclone descending. Tornadoes are good in that they have a limited lifespan (you won’t see three-day tornadoes, like you would a hurricane), but unlike hurricanes, we still don’t have the technology to predict where and when a tornado will pop up.

“Tornado outbreak” doesn’t have a specific scientific meaning – it mostly means a lot of tornadoes are spawned from a single storm. The worst outbreak on record was the “Super Outbreak” in April 1974. There were 148 tornadoes in 18 hours, with six being classed as F5 (the most destructive) and 24 classed as F4. About 315 people were killed in the U.S. and Canada and over 5000 people were injured. This history is one of the reasons that people are so concerned about tomorrow’s weather. The storm that is headed to Alabama passed through Texas earlier in the week and produced the largest tornado outbreak of 2010 to date – 32 tornadoes.

Tornadoes must have two fundamental ingredients: wind shear and some instability, like the aforementioned hot/cold and dry/wet condition along a front. Most of the time, you have some combination, like a little of one and a lot of the other. Meteorologists start getting worried when there is a lot of both. NOAA predictions are interesting to read, but you need a little background. There are multiple weather models because weather is fundamenteally difficult to predict. (Very much like the results of a Talladega race.) Meteorologists run several scenarios with the different models and try to figure out which one is most accurate for the particular situation. Our local meteorologist talks about ‘one model shows this and others show that, but I think the first one is right’. The closer the weather system gets to actually spawning a tornado, the more confidence we have that one or more of the models are accurate. Here’s part of the NOAA forecast with my comments.

SEVERAL FACTORS APPEAR TO BE COMING TOGETHER FOR A TORNADO OUTBREAK ACROSS THE REGION SATURDAY WITH A WIDESPREAD SEVERE THREAT CONTINUING THROUGH SATURDAY EVENING. THE KEY TO A TORNADO OUTBREAK SHOULD BE THE POSITION OF THE LOW-LEVEL JET. THE GFS AND NAM SOLUTIONS (GFS and NAM are two different models) VARY, WITH THE GFS FOCUSING THE LOW-LEVEL JET ACROSS NE LA (Northeast Louisiana) AND NW MS (Northwest Mississippi)SATURDAY MORNING WITH THE NAM FOCUSING THE LOW-LEVEL JET FURTHER SOUTHEAST IN SCNTRL (South Central) MS. AT THIS POINT…HAVE TAKEN A COMPROMISE BETWEEN THE TWO SOLUTIONS BUT AM FAVORING THE GFS SOLUTION WHICH IS SUGGESTING THE POTENTIAL FOR TORNADOES WILL BE GREATEST ACROSS NRN (Northeastern) LA…SRN/ERN (Southern/Eastern) AR AND WRN/NRN MS SATURDAY MORNING THROUGH EARLY AFTERNOON. Here’s the important part for us:
A POTENTIAL FOR TORNADIC SUPERCELLS SHOULD ALSO EXIST EWD (Eastward) ALONG A WARM FRONT INTO NRN AL (Northern Alabama) AND SWD (Southward) ACROSS THE WARM SECTOR ACROSS MS AND AL SATURDAY AFTERNOON. ANY SUPERCELLS THAT DEVELOP ACROSS THE REGION SHOULD ALSO HAVE A THREAT FOR LARGE HAIL AND WIND DAMAGE.
THE SETUP COULD BE FAVORABLE FOR STRONG TO VIOLENT TORNADOES AND A LONG-TRACK TORNADO WILL BE POSSIBLE. AN OUTLOOK UPGRADE TO HIGH RISK MAY BE NEEDED ACROSS PARTS OF THE REGION AS CONFIDENCE INCREASES CONCERNING THE MODEL SOLUTIONS. ALTHOUGH THE BRUNT OF THE OUTBREAK IS EXPECTED DURING THE MORNING AND EARLY AFTERNOON…SUPERCELLS AND WELL-DEVELOPED LINE-SEGMENTS SHOULD BE CAPABLE OF PRODUCING TORNADOES…LARGE HAIL AND WIND DAMAGE THROUGH SATURDAY EVENING.

As the figure at left indicates, the area with the highest probability of severe weather includes the Talladega racetrack. This is a prediction from NOAA, which is about as good as it gets when it comes to weather

For every Jim Cantore you see standing out in the middle of a tornado or hurricane showing people how bad the conditions are and why no one should be outside, there are a hundred meterologists at federal agencies and TV stations poring over the output of their models, trying to figure out which model is most correct so that they can give the maximum amount of warning to the areas that are in danger. Even though we can’t pin down the location, if you are or are planning on being out at the track, take this seriously and be careful.

Some Myths Debunked

• Opening windows does nothing. Yes, the pressure may drop outside, but it is almost impossible for the pressure differential to be so great as to cause the house to “explode”. There is actually evidence that opening windows is worse in terms of damage to the house. If it’s a really serious tornado, it is going to do some damage and it is not going to care whether your windows are open. (A tornado also can’t lift up your house and deposit it in Oz, but it gave me an idea for a funny story that involves Kevin Harvick as Dorothy and the media as the Munchkins.)
• Highway overpasses are not safe places during a tornado. Steel-reinforced concrete is strong, but not stronger than a tornado. If the overpass is hit by a tornado, it can fall and anyone in the vicinity is in danger of being hit by debris. If you think about it, the area underneath an overpass basically funnels all the wind through that area, so you are in much more danger being under an overpass than you are in your house.
• No geographical feature protects you from a tornado. They go over the river and through the woods, through cities, over hills, and basically wherever they care to go. Lying in a ditch is the best thing to do if you’re outside, but it is much better not to be outside.
• Motorhomes and RVs do NOT cause tornadoes; however, you are much more likely to be injured by a tornado or high winds in a RV or motorhome than you are in a permanent structure.

What to Do

What you SHOULD DO, especially if you are out at the racetrack:

• If you’re at home and planning on heading for the track, listen to the radio to make sure activities haven’t been delayed or cancelled because of the weather.
• Have a weather radio with fresh batteries and spares. Listen to the weather, watch it on TV, and be aware that you may need to take action on short notice.
• If you’re camping or RV’ing, have a flashlight and emergency kit that includes the basics, like bandages, antiseptic, etc.
• Make an emergency plan for your group – identify two places to meet if something happens and you are separated. One place should be near your campsite or seats and another should be a little further away, to be used if there is damage to the first area. Cell phone lines often become overloaded during emergencies, so don’t count on being able to reach each other on the phone.
• Don’t get falling down stupid drunk. You may need to think quickly. Wait until after the storm warnings have expired to enjoy the special pleasures of Talladega.
• If you hear sirens or radio/television reports that a storm is coming, get into a permanent structure if at all capable. My guess is that the safest place at Talladega if you’re out camping is in a ground-floor bathroom in a concrete structure. Like being on an airplane, identify two such structure because there are likely to be a lot of people with the same idea you have. If you can get underneath something heavy, like a sturdy table, a workbench, or anything else that would protect your head from falling debris, that’s even better.
• Remember that NASCAR fans share a unique bond that makes us more like family than strangers, even if we’ve just met. If someone needs help, help them — even if they are wearing a xx t-shirt (where xx is your least favorite driver’s car number).

I do not envy the folks at Talladega trying to guess the best way to proceed. I was at Richmond two years ago when there was a hurricane. The race was cancelled the day before. It was beautiful in Richmond that Sunday, but there was a lot of damage on most of the routes leading to the racetrack. NASCAR will probably get criticized no matter what they do, but I liked Jim Hunter’s attitude. “There’s a chance of bad storms, but there’s also a chance of Sun.” Let’s hope for the Sun this weekend.

I’ve gotten a little behind in my blogging. My Mom was diagnosed with cancer in February and passed away last week, which threw me for a bit of a loop in terms of catching up. But here it is, Texas race weekend and seven races into the year. So #6 conveniently comes the same weekend NASCAR announces their expanded recycling program.

Recycling is not entirely new with NASCAR. They’ve recycled tires through Goodyear for a long time, and Safety Klean recycles lots and lots of fluids – oils, transmission fluids, etc. That’s inside the garage, though and that’s a small fraction of the activity at the track.

NASCAR has huge events – Texas Motor Speedway can attract 170,000 + fans and a significant fraction of those come for two or three days.

The weight of an empty 20-oz. water bottle is about 20 grams (0.7 oz). A plastic Budweiser bottle weighs more, but let’s take this as a minimum. If each fan drinks two drinks in plastic bottles, we’re talking about 6,800 kilograms – almost 15,000 lbs of plastic bottles. That’s equal to a little more than four Sprint Cup cars (plus their drivers). I know there are a LOT of people who drink much much more than two beverages during the course of a weekend. And then there are the people who drink more than two beverages during the course of a yellow flag.

I talked with NASCAR’s Managing Director of Green Innovation, Dr. Mike Lynch, near the beginning of the year (when I planned on getting all these written) and he told me about some of NASCAR’s plans. In partnership with Coca-Cola Recycling, NASCAR is trying to ensure that a lot more of the waste generated at races is recycled. In the 2009 season, they recycled 80 tons and 2.5 million containers, which is a great start.

Let’s start with Mike’s credentials. He started out as a saxophonist – that’s his B.S. degree, but he moved fields to get a Ph.D. from the University of Miami in Developmental Psychology. That, in my opinion, gives him some unique credentials to deal with drivers! He won tenure at Purdue, but decided the ivory tower was not for him. He earned an MBA at the University of Chicago and became an entrepreneur, mostly working on green medical products among others. He sold that business, started another one and so on. In other words, he’s done a lot of different things with all types of customers and all types of topics.

The amount of recycling in 2009, even given that the recycling program isn’t active at all tracks, is clearly not anywhere near the numbers that end up in landfills. I wondered why NASCAR doesn’t recycle more. You do have to realize that I’m the kind of person who will carry a soda bottle home if it looks like the flight attendants are going to toss it in the trash instead of recycling it. I’ve worked with enough plastics to know that Plastics are Forever. Good for keeping soda fresh. Bad for the land, the sea and the air.

Mike Lynch brought a number of challenges to my attention — the kinds of things you don’t appreciate unless you are first-hand working on something. First off: Getting people to recycle requires placing a recycling container next to every trash container. I started counting trash containers today at TMS. Mike tells me that a small track like Richmond might have 500 trash cans, but a place the size of Daytona or Talladega requires more than 1200 bins to cover the 200,000 to 250,000 people who attend. Texas, I estimate, needs about 1000, plus one for every hauler in the Cup and Nationwide garages. Then you have to have people to empty the bins and take the contents somewhere. At some tracks, there is a remote location that is set up – not too far from the track – where they stage the recycling. That’s one of those things you don’t think about. I can store a blue garbage bag of recycling in the garage until the Friday pickup, but think about the volume those 15,000 lbs of bottles take up.

You also have to have the personnel to empty the recycling bins and make sure that the recycling gets separated from the trash. (The custodial ranks at TMS have orange vests that read “housekeeping”. Shouldn’t they read “track keeping”?) Someone has to make runs to and from the remote site. Mike mentioned that collecting recycling from the fans pretty much has to be a ‘single stream’ process, meaning one bin for everything recyclable (cardboard, glass, bottles, cans). In some locations, the recycling needs sorting – in others it doesn’t. They also have track personnel pick up bottles and cans from the grandstands after the races and add them to the recycling. The track gets market price for the recyclables, which hopefully helps defray their costs in setting up the bins, emptying them and sending them to the off-track facility.

Whew. That’s without the problems. For example, Daytona has Pepsi as a track sponsor and, since the NASCAR recycling program is doing by Coca-Cola, there is a problem there. This is one of the things about NASCAR that makes me really irritated. When it comes to doing good, there is no such thing as exclusivity. What I really want to see is a program whose first priority is getting as much recycled as possible and secondarily concerned with who gets credit. We’ve had similar problems with the educational materials we’ve been trying to develop to get students more interested in math and science: we can’t post them on YouTube, for example, because NASCAR Media group owns the rights and there’s some issue with Turner having web rights, etc. etc. etc. Like our educational programs, I am highly doubtful that anyone is making money on the recycling program. It’s fine for Dale Jr. to be exclusively pitching AMP energy drink, Wrangler Jeans and whatever else he wants, and he and Kasey can arm wrestle about whether there is room for more than one beverage at Hendrick Motorsports: I don’t care. There is no such thing as exclusivity when it comes to our planet.

Tying everything to a sponsor raises some other problems. Office Depot is sponsoring…, well, I’m not totally sure. Here’s what the press release says:

“Office Depot, along with Coca-Cola Recycling, will have co-branding on all NASCAR recycling elements at the track in Texas, including special locations for ink cartridge recycling. The Office Depot show car program in the local area also will promote recycling to fans, including race ticket giveaways providing an incentive for fans to “grow greener.”

I don’t know about you, but the chances that I remember to bring my empty toner cartridges with me to the track is pretty slim. Staples gives me a $3 credit for every one I return to them, and given my office supply habit (awaiting a 12-step program), that’s a better deal for me. Now, if Office Depot gives me something NASCAR-related year round for bringing my cartridges to me, I would patronize them over Staples just because they support the sport and won’t continue to do so unless they are getting business out of it.

NASCAR is a little cautious about pushing green, as there are those uninformed people who think that motorsports are about as wasteful a sport as there is. Not true.

Do the math: Even on a weekend that includes a Cup race, a Nationwide race and a Truck race, the total amount of gasoline used for the races and practices is less than the amount the whole country uses in ten seconds. NASCAR wastes less gas than I do when I have to run back to the grocery store for something I forgot, or back to work because I can’t remember whether I turned off the diffusion pump or not.

NASCAR is in an important position because they can influence so many people. That means they have the potential for doing great good. It also means they have the potential for doing great damage.

The tree planting program is a great example. NASCAR is committed to planting ten trees for every green flag that appears in the Cup race. Great PR move, except the amount of carbon dioxide (which is what is meant to be remedied by the trees) is determined by how many gallons of gasoline are combusted. It is totally unrelated to the number of green flags. Here’s a great example of what we call in education a ‘teachable moment’ and they’ve blown it.

One gallon of gasoline produces about 19.4 pounds of carbon dioxide. You don’t need much to believe this, just the ability to balance a chemical equation and do some simple multiplication. No calculus, I promise.

The average NASCAR Sprint Cup car gets about 4 mpg under green and 8 mpg under yellow. Let’s just assume, again overestimating, that all 43 cars run 500 miles without any cautions. That would correspond to 43 x (500/4) = 5375 gallons of gasoline. At 19.4 pounds of CO₂ per gallon of gasoline, the average Cup race is responsible for about 105,000 pounds of CO2.

Remember that people breathe in oxygen and exhale carbon dioxide and plants take in carbon dioxide and release oxygen. The perfect symbiotic relationship, which is why people plant trees to offset carbon emissions.

The question of how much CO₂ a tree can remove from the environment is an open (and complicated) question. It depends on what type of tree and how long you allow the tree to grow. Bigger trees take up more CO₂. To NASCAR’s credit, they are committed to planting larger trees, which removes more CO2 from the environment faster. A single large “mature” tree can take up anywhere from 25 to 70 lbs of CO₂ per year. In the best case (70 lbs/year), you’d need 1500 trees to absorb all of the CO₂ in one year. Of course, the trees should live for more than one year, so you could amitorize the carbon remediation over several years.

The whole question of how much carbon dioxide a tree can remove from the atmosphere is uncertain, so I’m a little skeptical of the whole idea of claiming that one can mitigate emissions by planting trees — especially if you’re planting trees without providing for their continued maintenance. There are a couple of studies that suggest that the majority of trees planted for carbon remediation never receive any attention after planting and thus never serve the purpose for which they were planted.

I suppose that there are people who will do something simply because a NASCAR driver or crew chief tells them it’s good. I really hope that this is a minority of people. I hope the majority of people want to understand why they are doing something rather than just doing it. But even if that’s not the case, it’s better for people to do the right thing without knowing why than to do the wrong thing. Kudos to NASCAR for doing what they’re doing – but there is more they could be doing.

I was frantically trying to finish this video blog this morning and still make my plane to Florida, where I’m looking forward to covering the 12 hours of Sebring American Le Mans Series (presented by Patron Tequila) race. You’ll have to excuse the glitches in the video editing while I am figuring out this new mode of communicating!

I wake up in the morning listening to our local NPR station. A couple weeks ago, they said that the George Bush Turnpike was closed due to “a buckle in the road”. My husband commented that he knew Texans had big belt buckles, but he didn’t think they were big enough to shut a whole side of the tollway.

Well, the buckle they were talking about was actually three feet high and spanned two lanes. Apparently, the heavy rains we had received created a lot of pressure in the adjoining retaining wall and that pressure pushed the pavement until it buckled and formed our own little miniature mountain range right there in Carrollton.

The problems at Daytona last Sunday weren’t quite of that magnitude (the pothole was about 9″ x 15″ and only 2″ high, but that tiny pothole impacted a lot more people. Including me, who had assured my husband that the race certainly would be over by five as he planned Valentine’s dinner. What happened and how could it have been prevented?

(photo Bill Friel)

Let’s start with thermal expansion. If you’ve ever had a lid stuck on a jar, or a ring stuck on your finger, you may have tried running the jar or the ring under hot water. The metal jar lid would expand faster than the glass jar, thus loosening the seal and allowing you to remove the stubborn lid. That’s because different materials expand at different rates. Metals expand faster than glass and fingers. (The water also provides some lubrication and in the case of jars, may dissolve anything sticky that might be inbetween the threads.)

Most things expand when heated and contract when cooled. Not water. This is good and bad. On the good side, ice is less dense than water, which means that ice can float on top of a pond while warmer, denser water goes to the bottom. The fish and anything else that wants to survive also goes to the bottom. On the bad side — as you know if you’ve ever left a bottle of soda or juice in your car overnight when it got really cold — water expanding at the wrong time can be a mess.

Water freezing and thawing can wreak havoc in other places. Putting in lawn edging in the North is an exercise in futility because the freeze/thaw cycles push the edging up so that, by April, it’s lying on the ground.

The word ‘cycles’ here is important. Most materials are designed to handle constant loads. A car rolling along a flat surface exerts about the same force everywhere along the surface. When you subject a material to repeated cycles of pulling and pushing on it, eventually, it breaks. You can bend a paper clip back and forth a couple of times, but it gets harder and harder to do, and then finally breaks. Each time you bend the paper clip, you make a little change in its microstructure. It’s like a game of pick-up sticks (or Kerplunk). Everything is fine up to a point, but when you push just a little too far, the whole thing comes down.

Normal temperature changes outside make most things expand and contact. There are joints in concrete sidewalks, for example, to allow for this expansion. Otherwise, two slabs of concrete would start pushing against each other and you’d have your own miniature version of plate tectonics.

Asphalt is made up of two components: aggregate (small pieces of rocks) and binder. Go get a bunch of rocks roughly 1/2 inch in diameter and put them in a jar. Try to pack them as closely as possible. It’s not easy to do, and if you don’t believe me, fill the jar up with water, then measure how much water you got in there.

The rocks are mixed with a liquid binder to hold it together, but in the end, asphalt looks like a sponge: rocks held together by binder, with a little bit of air space inbetween. A typical composition for asphalt might be 80% rock, 15% binder and 5% air voids. Here’s a picture from “The Idiot’s Guide to Highway Paving” showing some asphalt close up.

You want some porosity in the asphalt. Porosity helps asphalt absorb water. A completely smooth, impervious surface would take a very long time to dry and would be more prone to hydroplaning than a rough surface.

The pores, however, cause problems, too. When water gets between stones and freezes, it exerts stress on the asphalt. Not a lot of stress, but enough cycles of stress will eventually produce weak spots and finally cracks. Once a crack is started, it’s very hard to stop (just like runs in nylons) and everytime a car goes over it, the crack gets wet. The weather in Florida was abnormally wet and cold the last few months. Don’t forget that Daytona was literally underwater last summer.

“Well, why didn’t they take that possibility into account?”, some of you are asking. If there is one thing we ought to be teaching in school science, it is that science never has absolute solutions. You can only increase downforce if you’re willing to pay a price in terms of drag or engine heating.

Likewise, if you engineered a track that was totally impervious to freezing and thawing, it wouldn’t drain well and would take a long time to dry when wet. Florida is much more likely to have rain and a need for lots of track drying than it is to have freezing. No track design is perfect. Although asphalt has been in use for many years (the Sumerians used it way back in 3000 B.C. as an adhesive on statues), we don’t have a lot of data on how highly banked asphalt racetracks that see speeds of 200 mph behave. There are really only two superspeedways, both constructed 1959-1960 and you can tell from the racing that they have very different characteristics, despite their apparent similarities.

Asphalt is not an easy material to work with, either. You start with crude oil, remove everything that seems useful (gasoline, diesel, oil, paraffin, etc.) and the sticky, goopy mess left over is used to make binder. You’ve probably seen (and/or smelled) asphalt machines puffing smoke near highway construction sites. The binder softens when it is warm and hardens when cool. Asphalt is usually laid down around 275-300 degrees Fahrenheit and gradually cools to a solid.

Liquid asphalt patches often consists of asphalt binder in a solvent — the same way pigment molecules are suspended in a solvent to make paint. You apply the liquid and wait for the solvent to evaporate, leaving behind a solid. The problem is that evaporation usually takes a long time. A re-surfaced asphalt driveway usually needs a day or two before it’s ready to be used. Heating will quicken the process, which is why the track workers were using a blowtorch on the patched area. Of course, the area that had the problem was the one part of the track that wasn’t in the Sun and thus was colder than everywhere else!

Eventually, they literally turned to Bondo. (My first car was a ’69 Buick LeSabre, so I know all about Bondo!) Bondo is a two-part putty that cures via a chemical reaction that is significantly less sensitive to temperature than asphalt patches. Of course, Bondo won’t stick as well to asphalt as asphalt sticks to asphalt, so Bondo is not the ideal solution. There’s that tradeoff again: you can make a fast repair that doesn’t last very long, or a slow repair that lasts longer. With a race in progress and FOX rapidly reaching the point where they were ready to interview drivers’ dogs because everyone else had already been interviewed, any repair that would get us to the end of the race was the right one.

Repaving is estimated at about $20 million dollars, and there’s no guarantee that (if it had been done between February and July ’09), the torrential rains of summer ’09 and the cool weather wouldn’t have caused problems. The next repave is tentatively scheduled for February 2012. Repaving can totally change the character of a track and not always for the better. They have plenty of time to patch the track between now and July (although there are other events scheduled for the track). An in-depth evaluation by an engineering company is in process. Whether patching will be sufficient or a total re-paving is necessary will be determined by the results of that evaluation. And while the folks doing the evaluation are some of the best in the business, the nature of the world is that there are no guarantees. The only Law of Nature that is certain is Murphy’s Law.