Why Do NASCAR Oval Tracks Have Banking?


Why Do NASCAR Oval Tracks Have Banking

NASCAR is famous for racing on oval tracks, and the majority of the NASCAR Cup Series races to this day still take place on ovals. However, an oval is a 2D shape, and the tracks have to be three-dimensional to be built. The Oval tracks are built with added banking, which is the steepness of the incline of the circuit, and we wondered why NASCAR used banking on Oval Race tracks.

NASCAR Oval tracks are banked to provide race cars with the optimum downforce, friction, and centrifugal force to corner at high speeds. Banking on Ovals pushes the car onto the track.  Without banking centrifugal forces push the car diagonally, resulting in a battle between the force and the friction of the tires.

We take a look at the racetracks and their banking below and see what difference banking makes to a track and the NASCAR cars racing around it, we also look at the oval tracksOpens in a new tab. with the most and least banking in the season.

Why Do Oval Race Tracks Have Banking?

There is not a required angle for the banking set out in the NASCAR regulations, and so the banking can be added at different angles, and there are a variety of angles on the calendar, giving each track slightly different characteristics.

Banking is used due to the physics of the racing, which is always considered during circuit or vehicle construction. When turning, NASCAR cars have a force due to their weight and centripetal force which acts diagonally downwards. However, when banking is added to tracks the force acts downwards on the tires, meaning that maximum grip is achieved, and the chances of skidding or crashing are reduced.

In addition, it means that less force acts sideways. The increased grip also allows the cars to turn faster, increasing the cornering speed which leads to great performance increases, and straight-line speed is often maximised.

Essentially, the banked turns keep the cars tilted inwards, rather than outwards where they would risk skidding or hitting a wall. The cars are also very fast, and they would likely fly off the track if some banking was not added during construction.

It has been proven that NASCAR’s banked turns create both frictional forces for the tires, as well as a centripetal force for the vehicles.

Differences in Driving an Oval and a Road Track

Ovals circuits have been proven to be more dangerous than road courses, and they are raced at higher speeds. In addition, none of the road courses that NASCAR races on have any form of banking, so the two types of track are very different to drive.

Despite the fact that ovals are more dangerous and faster, people have often called them easy to drive due to the fact that the drivers only have to turn left and stay at or around full throttle. However, this is simply not true and banked oval driving requires different skills.

The banking allows rubber to build up easily, due to the fact that the turns have a wide radius meaning that drivers can drive on the outside line, which would simply not be possible on a road course. The fact that the banked ovals are short also means that more laps are driven, and so more rubber builds up adding to the already increased grip.

Road courses also sometimes use standing starts, but this is not used Ovals especially in NASCAR as it would be impossible to keep the cars steady and still on the banked sections, which are also built on the straightsaways.

The ovals are also repetitive, and so the drivers have more confidence to use the full capability of their cars, particularly on a high-banked oval where the risk of spinning is much lower, barring bumps and scrapes.

What Would Happen if Ovals Race Tracks were not Banked?

Removing or reducing the banking at the oval circuits would reduce the speed of the cars around the turns. When on a flat curve, only the friction of the car is holding it to the circuit, whilst the centrifugal force is pulling the car off of the track.

This leads the cars to be pushed to the outside. Removing banking would reduce the cornering speed as the grip level would be reduced. The speed would slow down, and those that push the limits too far would spin or skid.

However, some people believe that the safety of the tracks would increase if banking was not used. Fatal wrecks can occur at ovals tracks in NASCAROpens in a new tab., and some people put the blame on the banking. In truth, the banking is essential for the stock cars due to the low downforce levels.

Formula One no longer uses banked tracks as the F1 cars have enough downforce to support themselves, but they previously did.

The banking is no longer needed in F1, but NASCAR has to use it due to their lack of downforce. The danger of NASCAROpens in a new tab. racing at ovals would increase without it.

Why Do NASCAR Oval Tracks Have Banking

Which Oval Tracks Have the Steepest Banking?

The oval layout is widely used, but the shapes and banking levels are different at every venue. The banking at some tracks is very steep, notably at the Talladega Superspeedway which has a banking angle of 33° on its first two turns, an angle of 32.4° on its third turn and an angle of 32.5° on its fourth and final turn.

These high banking angles were pioneered by William France, the founder of NASCAR who constructed the Daytona International Speedway. He wanted the track to have the highest banking that was possible at the time, to increase the speeds and give fans a better view of all of the action.

The construction company had to excavate over one million square yards of soil to build the harsh banking, which has a banking angle of 31° on each of the four turns, as well as an angle of 18° on the start and finish line.

These two tracks were perfect for racing when they were first constructed, but in the modern era, they cause huge packs of cars due to the drafting effect and restrictor plates introduced after the crashes of 2001. ( see more details here)

Bleacher Report have ranked Daytona International SpeedwayOpens in a new tab. and Talladega Superspeedway as the two most dangerous tracksOpens in a new tab. in NASCAR, proving that banking makes the tracks faster and more grippy, but also more dangerous.

Which Ovals Race Tracks have the Least Banking?

The flattest oval circuit on the NASCAR Cup Series schedule is the New Hampshire Motor Speedway, which has a variable banking angle, between 2° and 7°, on each turn.

The straights have just 1° of banking. The Indianapolis Motor Speedway is another very flat NASCAR oval, with banking of just 9° on the turns, with the straights having no banking at 0°.

The road courses have no banking, but they tend to have lots of elevation changes instead.

What is the Banking on NASCAR Oval Race Tracks.

As we have mentioned Talladega has the steepest banking in oval NASCAR tracks, at 33 Degrees in some places, and others like the road tracks or new Hampshire having just 9%,. However there are over 25 other tracks used throughout the NASCAR cup series. We take a look at the banking for all the current NASCAR tracks below.

We have included our research into a table below with all both the Corner banking angles and the straightaways banking angles for the tracks used in the 2022 NASCAROpens in a new tab. Cup series as a reference.

NASCAR Race TrackCorner / Turn BankingStraightaways Banking
Los Angeles Coliseum2.5 Degrees2.5 Degrees
Daytona International Speedway31 Degrees (18 – tri-oval)2 degrees
Auto Club Speedway14 Degrees11 and 3 Degrees
(front and back stretch)
Las Vegas Motor Speedway20 Degrees9-12 degrees
Phoenix Raceway8-11 Degrees3 Degrees
Atlanta Motor Speedway28 Degrees5 Degrees
Circuit of the AmericasRoad TrackRoad Track
Richmond Raceway14 Degrees2-8 Degrees
Martinsville Speedway12 Degrees0 Degrees
Bristol Motor Speedway26-30 Degrees6-10 Degrees
Talladega Superspeedway16.5 (tri-oval) 33 Degrees
Corners
3 Degrees
Dover Motor Speedway24 Degrees9 Degrees
Darlington Raceway23-25 Degrees2-3 Degrees
Kansas Speedway17-20 Degrees5-11 Degrees
Texas Motor Speedway20 -24 Degrees5 degrees
Charlotte Motor Speedway24 Degrees5 degrees
Gateway Motorsports park9-11 Degrees3 Degrees
Sonoma RacewayRoad TrackRoad Track
Nashville SuperSpeedway14 Degrees6-9 Degrees
Road AmericaRoad TrackRoad Track
New Hampshire Motor Speedway2-7 Degrees1 Degree
Pocono Raceway6 -14 Degrees
Indianapolis Motor Speedway0 Degrees9.2 Degrees
Michigan International Speedway18 Degrees5 -12 Degrees
Watkins Glen InternationalRoad TrackRoad Track
Homestead-Miami Speedway18 – 20 Degrees3 Degrees

Final Thoughts

As you can see NASCAR Oval tracks all are constructed with banking to provide drivers with more grip and to push their cars onto the surface of the road. Including banking on Oval tracks mitigates the forces pushing the car diagonally, and allows cars to not just rely on the friction of their tires, but also the centrifugal forces nwo pushing the car down and not at an angle.

Cornering without banking on an oval would have to be performed at much lower speeds to prevent the centrifugal forces spinning the cars off the track.

References

https://www.sportskeeda.com/nascar/news-nascar-exhibition-los-angeles-clash-low-banking-angle

https://buildingspeed.org/2020/02/04/daytona-banking/

https://iracing.fandom.com/wiki/World_Wide_Technology_Raceway_at_Gateway

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