NASCAR tracks have undergone quite an evolution over the years, not just in terms of size and length, but also in what they’re made of. Once primarily dirt, today’s tracks are composed of a different material. So, you may wonder exactly what NASCAR tracks are made of.
Most NASCAR tracks are made of asphalt, but a few of them are also made from concrete. NASCAR also brought back one dirt track race starting in 2021, in Bristol. NASCAR tracks vary in smoothness, and concrete tracks are generally the smoothest ones on the schedule.
Below, we will reveal just how many NASCAR tracks are made from asphalt, and how much asphalt is required to sustain the rigors that NASCAR brings. We will also touch on the key differences between asphalt, concrete, and dirt tracks, before discussing the costs of resurfacing a NASCAR track.
Are All NASCAR Tracks Asphalt?
Asphalt tracks have dominated the NASCAR scene since the R.J. Reynolds Tobacco Company took over sponsorship in 1971. The company wanted to revamp NASCAR’s image, which at the time saw many more short tracks than we have on the circuit today. While asphalt’s popularity was growing at the time, NASCAR still held many races on dirt tracks.
In 1971, they stopped racing on dirt surfaces (until 2021, when NASCAR started holding an annual dirt event at Bristol). Since 1971, asphalt has become the most common track surface in NASCAR. However, there is still some concrete on the NASCAR schedule.
Martinsville may be predominantly asphalt, but you will find concrete in the turns. Dover Motor Speedway had an asphalt surface until 1984, before they switched to concrete. In 2021, NASCAR started racing at Nashville Superspeedway, which also has a concrete surface. And finally, the New Hampshire Motor Speedway is made of asphalt and granite.
How Thick Is The Asphalt On A NASCAR Track?
The asphalt on a NASCAR track is 5 inches thick in total, or about 13 centimeters. It’s made up of 3 layers, and each layer is no less than 1.5 inches thick (3.8 cm).
Most NASCAR tracks are paved with asphalt, and the track surface must be built to withstand 36-40 cars weighing up to 3,400 lb (1,540 kg) for between 250 and 600 miles (402-966 km). These tracks also host other auto racing events throughout the year, and they must also withstand the elements.
This calls for three thick layers of asphalt. The first layer, called the Base Layer, is 2 inches (5 cm) thick. The next layer is the Middle Layer, and it measures 1.5 inches (3.8 cm). The Middle Layer requires careful measurements, so the crew uses a profilograph to check for any dips and bumps. And while it is impossible to cover them all, there are usually maximum limits per mile of track.
Once the middle layer passes the profilograph test, the crew lays the Top Layer, also called the Wearing Surface. This layer is also 1.5 inches (3.8 cm) thick. Overall, the asphalt on a NASCAR track is 5 inches (13 cm) thick, allowing the track to withstand the heavy lateral loads that come with high speeds and constant turning.
When you compare asphalt on a NASCAR track to that on your local interstate, a NASCAR track’s thickness is substantially lesser. While each track must support a lateral load, the interstate must support vertical loads, given the number of large vehicles, like semi-trucks, constantly using them to transport products and materials.
Fast Tracks Call For Special Challenges
The fastest tracks on the NASCAR circuit must involve modified equipment designed to work at steep angles in the turns. This is because fast tracks all feature steep banking, allowing cars to maintain much of the speed they gained on the straights. At the top of the banking, bulldozers with an arm attached must work over the retaining wall.
You will see cables attached to these arms, which prevents the equipment from moving down the banking and into the infield. The crew must continually adjust tension on the arms, or else the final product would be an uneven pavement. This is also true for tracks looking to reconfigure themselves with steeper banking, which was the case with Homestead-Miami.
Homestead As An Example
The track had just 6 degree banking until 2002. When they reconfigured the venue for 2003, banking in the turns increased to 18-20 degrees. This is one reason you see some tracks with steep banking made of concrete, as it can handle the high stresses of these tight, banked corners.
Tracks like Dover (24 degree banking), and Bristol (24-28 degree banking), are also made of concrete for this reason. However, tracks like Talladega, Atlanta, and Daytona are made of asphalt, so when they reconfigure or repave these tracks, you will see specialized equipment used to do so.
KEY POINTS
• Not all NASCAR tracks are made of asphalt
• Some are all-concrete, or feature concrete in the corners
• There is also one dirt track event on the schedule, at Bristol
What NASCAR Tracks Are Made Of
| Track | Type | Length | Surface |
| Atlanta | Intermediate Oval | 1.55 miles (2.5 km) | Asphalt |
| Auto Club | Superspeedway | 2 miles (3.2 km) | Asphalt |
| Bristol | Short Track | 0.533 miles (0.85 km) | Concrete |
| Bristol Dirt | Short Track | 0.533 miles (0.85 km) | Dirt |
| Charlotte | Intermediate Oval | 1.5 miles (2.4 km) | Asphalt |
| Charlotte Roval | Road Course | 2.3 miles (3.7 km) | Asphalt |
| Chicago Street Course | Road Course | 2.2 miles (3.5 km) | Asphalt |
| Circuit of the Americas | Road Course | 3.4 miles (5.5 km) | Asphalt |
| Darlington | Intermediate Oval | 1.3 miles (2.1 km) | Asphalt |
| Daytona | Superspeedway | 2.5 miles (4 km) | Asphalt |
| Dover | Intermediate Oval | 1 mile (1.6 km) | Concrete |
| Homestead-Miami | Intermediate Oval | 1.5 miles (2.4 km) | Asphalt |
| Indianapolis Motor Speedway Road Course | Road Course | 2.4 miles (3.85 km) | Asphalt |
| Kansas Speedway | Intermediate Oval | 1.5 miles (2.4 km) | Asphalt |
| Las Vegas | Intermediate Oval | 1.5 miles (2.4 km) | Asphalt |
| Los Angeles Memorial Coliseum | Short Track | 0.25 miles (0.4 km) | Asphalt |
| Martinsville | Short Track | 0.526 miles (0.85) | Asphalt/Concrete |
| Michigan | Intermediate Oval | 2 miles (3.2 km) | Asphalt |
| Nashville | Intermediate Oval | 1.3 miles (2.1 km) | Concrete |
| New Hampshire | Intermediate Oval | 1 mile (1.6 km) | Asphalt/Granite |
| North Wilkesboro | Short Track | 0.625 miles (1 km) | Asphalt |
| Phoenix | Intermediate Oval | 1 mile (1.6 km) | Asphalt |
| Pocono | Superspeedway | 2.5 miles (4 km) | Asphalt |
| Richmond | Short Track | 0.750 miles (1.2 km) | Asphalt |
| Sonoma | Road Course | 1.9 miles (3 km) | Asphalt |
| Talladega | Superspeedway | 2.7 miles (4.35 km) | Asphalt |
| Texas | Intermediate Oval | 1.5 miles (2.4 km) | Asphalt |
| Watkins Glen | Road Course | 2.45 miles (4 km) | Asphalt |
| World Wide Technology Raceway | Intermediate Oval | 1.25 miles (2 km) | Asphalt |
Asphalt vs Concrete NASCAR Tracks
Asphalt is more flexible than concrete, and it also transmits stress in a narrower area, meaning asphalt tracks must be thicker. Concrete is harder, and therefore able to transmit stress over a wider surface. Asphalt can wear out faster, especially in high banked sections of the track. This is why you’ll sometimes see concrete used in the corners of asphalt tracks.
Besides concrete being stronger than asphalt, it may also create more grip when laid in a certain way. Asphalt’s grip varies, given the type of bitumen and aggregate used. The faster the bitumen wears out, the faster it exposes the aggregate. Friction caused by the tires will deplete this aggregate, and this weakens the track, requiring more frequent resurfacing.
Track Color Plays A Role
Asphalt tracks are black while concrete tracks carry a lighter color. The black asphalt track absorbs much more radiation from the sun than the lighter concrete. This causes asphalt to heat up faster than concrete, making the track hotter, which can offer more grip, but also higher tire wear, and if it’s excessively hot, the drivers may end up losing grip sooner.
Asphalt vs Dirt NASCAR Tracks
While temperature affects asphalt tracks, conditions change on dirt tracks on virtually every lap with cars driving over the surface, creating more grooves throughout the event. As the race progresses, the cars also kick up a lot of dust. This makes it even tougher for tires to grip the track.
The dirt can also pack down, creating a slippery surface, providing even more of a challenge for tire grip. This creates a unique challenge for the entire NASCAR team.
Dirt Tracks Require Different Tires
Because of the volatility on dirt tracks, NASCAR uses different tires when they race there. On asphalt and concrete, you see slick tires (unless it’s raining on a road course, where wet tires may be used). On dirt, they need special grooved tires with treads that resembles a checkerboard, called tread blocks.
Goodyear has optimized the dirt tire specifically for better grip on the dirt surface. Besides grooved tires featuring tread blocks, the tires required for dirt surfaces are bias-ply instead of radial. Bias-ply tires are more flexible, which makes them better for off-road racing than radial tires.
How Smooth Are NASCAR Tracks?
NASCAR tracks vary in how smooth or rough they are from year to year. Smoothness is something NASCAR regularly monitors, measuring their variance from the highest bump to the lowest dip in micrometers. Martinsville, which measured 118 micrometers in variance, was the smoothest NASCAR track in 2019.
Dover, measuring 120 micrometers, was second, and Bristol, at 128 micrometers, was third smoothest. What is interesting about this is that these three tracks were the only full or partial concrete surfaces NASCAR raced on at the time, as they did not expand to Nashville until 2021. So, the concrete tracks are generally smoother than their asphalt counterparts.
Watkins Glen, at 168 micrometers, was fourth. Michigan, the first asphalt oval track on the list, was fifth, at 216 micrometers. The roughest track on the list was Atlanta Motor Speedway, which measured at a whopping 682 micrometers. This number will have changed since 2019, considering Atlanta’s resurfacing and reconfiguration for 2022.
KEY POINTS
• While most NASCAR tracks are made of asphalt, concrete does offer some advantages
• Dirt tracks present very unique challenges to the drivers and teams
• The smoothest NASCAR tracks tend to be made of concrete
How Often Are NASCAR Tracks Resurfaced?
NASCAR tracks are resurfaced as and when required, rather than on a regular basis. However, most NASCAR tracks, regardless of the type of track, are resurfaced within around 20 years or so.
The Atlanta Motor Speedway was resurfaced in 2022, which was the first time it had been resurfaced in 25 years. Auto Club Speedway, which was last resurfaced in 1996, has even older asphalt than Atlanta. Dover, an all concrete track, has the oldest surface, which last had work done to it in 1995.
Interestingly, NASCAR wanted to resurface Atlanta in 2017, but backlash from the drivers delayed that for five seasons. Therefore, NASCAR only resurfaces tracks when they believe the surface has worn down enough to require resurfacing. Many drivers love the bumps and so-called character affiliated with older surfaces, so NASCAR may delay projects at the drivers’ discretion.
How Much Does It Cost To Resurface A NASCAR Track?
It costs around $200,000 per mile to resurface a NASCAR track, although for some tracks it may be 10 times that. Larger, wider tracks will cost more than shorter, narrower tracks. Martinsville, for example, would cost less money to repair than Talladega, since it is just over half a mile long.
Talladega, sitting at 2.7 miles (4.35 km) in length and nearly five lanes wide, would cost at least $675,000 to resurface. Note that a resurfacing may also call for reconfiguration, which was the case at the Atlanta Motor Speedway. If they reconfigure the banking, you can expect it to cost up to seven figures at larger tracks, and closer to the middle six figures at shorter tracks.
KEY FACT: Watkins Glen was repaved in 2015 at an estimated total cost of $12 million, or about $3-4 million per mileFinal Thoughts
Most NASCAR tracks are made of asphalt, but you see a few concrete surfaces on the schedule too. NASCAR went over five decades without a dirt race, but they brought back an annual dirt event in 2021 at Bristol. Tracks are usually resurfaced within two decades, but some surfaces last for 25 years or more.
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