Why NASCAR Tracks Have Banking

NASCAR tracks are banked so cars can corner faster and more safely: the angled surface redirects part of a car’s weight toward the center of the turn, reducing reliance on tire friction, widening the usable speed range in corners, promoting multiple racing lines, and aiding drainage and spectator sightlines. This design shapes the character of every oval, from tight short tracks to high-speed superspeedways.

The physics behind banked turns

In a flat corner, tires must generate nearly all the lateral force needed to turn the car, which limits speed and stability. Banking changes that balance. On an inclined surface, the normal force from the track has a horizontal component that contributes to the inward (centripetal) force required to follow the curve. As the banking angle increases, more of this needed force comes from the track itself and less from tire grip. At a “design speed” that depends on the corner’s radius and banking angle, a car could in theory make the turn with little or no lateral tire slip. This means higher cornering speeds, a broader margin for error, and more consistent handling across a range of speeds.

What banking does for racing and safety

The following points outline how banking affects competition, drivability, and risk management in NASCAR.

• Higher cornering speeds: Banking allows cars to maintain far greater speeds through turns than on flat tracks, raising average lap speeds and reducing lap time.
• Stability and a wider speed window: Because the track provides part of the turning force, cars are less likely to slide at a given speed, giving drivers more confidence and leeway in traffic.
• Multiple racing grooves: Progressive banking (angle increasing toward the wall) encourages different lines—low, middle, and high—supporting overtaking and side-by-side racing.
• Pack dynamics at superspeedways: Steep banking at Daytona (about 31 degrees) and Talladega (about 33 degrees), combined with tapered spacers that limit horsepower, promotes tight packs and drafting at ~190–200 mph.
• Safety margins: While higher speeds raise energy in crashes, banking can reduce spins from tire overload in corners by lowering the lateral friction demand; modern SAFER barriers, catch fencing, and car design address the remaining energy management.
• Drainage and visibility: Banked surfaces shed water toward the apron and drains, speeding track drying, and also improve sightlines for fans on the outside grandstands.

Together, these effects make banked ovals more raceable and resilient—supporting high-speed competition while controlling how forces act on cars and tires.

Degrees of banking vary by track

Track designers tune banking to match the venue’s length, corner radius, and intended style of racing, resulting in distinct personalities across the NASCAR schedule.

• Short tracks (roughly 0.5–1.0 mile): Banking ranges from modest to mid-20s degrees. Martinsville is relatively flat (around 12° in the turns), favoring braking and mechanical grip, while Bristol is notably steeper (mid-20s), enabling sustained corner speed and multiple grooves.
• Intermediate ovals (1.5–2.0 miles): Typically 12–24 degrees, with many using progressive banking. Charlotte is about 24°, Kansas and Las Vegas feature progressive profiles up to roughly 20°, and Atlanta’s 2021–22 reprofile increased banking to the high 20s, yielding superspeedway-style packs despite its 1.54-mile length.
• Superspeedways (2.5+ miles): Steep banking and long, sweeping turns define Daytona (about 31°) and Talladega (about 33°), enabling very high cornering speeds and sustained drafting.
• Road courses and hybrids: Dedicated road circuits usually employ mild positive camber for drainage and balance, while hybrid layouts like the Daytona road course incorporate heavily banked oval turns alongside flat infield sections.

These choices influence not just top speed but the kind of racing fans see—tight packs, tire strategy, or brake-and-throttle rhythm battles.

Trade-offs and design choices

Banking is part of a broader design calculus. More banking boosts speed and stability but increases construction cost, structural load on the pavement, and the energy that must be managed in incidents. Track builders balance geometry (radius, length), target speeds, tire and car technology, and safety systems to produce a desirable racing product for current and future car packages.

Progressive vs. constant banking

Constant banking keeps the same angle across the width of the corner, typically funneling cars into a preferred groove. Progressive banking increases the angle from the inside lane toward the outside wall, making the high line more viable at speed and encouraging side-by-side racing as tires wear and setups evolve across a run.

What engineers consider when setting banking

Several technical and practical factors shape the final banking profile at a track.

• Corner radius and desired cornering speeds for the series that will race there.
• Vehicle packages (aero, horsepower limits such as NASCAR’s tapered spacers at superspeedways, tire construction and compounds).
• Surface durability, drainage patterns, and climate (how fast the track can dry after rain).
• Safety infrastructure (SAFER barriers, runoff, fencing) calibrated to the expected speed envelope.
• Sightlines and fan experience, including how multiple grooves affect passing and race complexity.

The result is a tailored profile that fits the track’s role on the schedule and the racing style organizers want to encourage.

Summary

NASCAR tracks have banking because angled turns harness physics to let cars corner faster and more predictably by shifting some of the turning load from tire friction to the track itself. The amount and style of banking—constant or progressive—directly shape racing lines, passing opportunities, safety margins, drainage, and the overall character of each venue, from flat, technical short tracks to high-speed, draft-heavy superspeedways.