As automobile companies pursued improved performance and technology and racing became a popular sporting event, the types of circuits available began to change. Circuits were built to incorporate the conditions that can be found on standard roads while preserving the terrain to the maximum extent possible.

Take the Circuit of the Americas (COTA), for example, built in Austin, Texas in the United States. The circuit is famous for having barely altered the natural terrain that is unique to the area. It contains various terrain types featuring conditions including steep uphill and downhill roads, as well as sharp curves and corners.

In addition to circuits designed to preserve the natural terrain of an area, artificial circuits have also emerged. Typical examples of this include urban circuits in Monaco, Singapore, and Saudi Arabia. Since they temporarily transform public roads in the city into racing circuits, these circuits emanate distinctive urban vibes.

Seemingly benefitting from a high degree of freedom in circuit construction, in reality, these circuits are built according to very strict standards.

Additionally, the circuits are approved and rated by the International Automobile Federation (FIA) according to applicable standards.

Only the tracks that gain FIA's Grade 1 license are allowed to host Formula One races, for example. The required standards to obtain the Grade 1 license are as follows:

First, tracks must be at least 3.5km long in total. Straights cannot be longer than 2km and circuits should not exceed 7km in length. If the course is too long, the race time per lap would be longer, thus posing greater safety concerns.

Tracks must be at least 12m wide at all points and there are strict standards applied to corners as well. For instance, the first corner must provide a change of direction of at least 45 degrees, have a radius of under 300 meters, and the starting line should precede the first corner by 250 meters.

The space between the different positions for the racing cars to remain stationary before the signal is given to start the race is also standardized. For general circuits, the grid spots must be spaced 6m apart, however, for Grade 1 circuits, this rises to 8m. In addition, the circuit is designed to meet the strict standards in terms of proportion of the pit straights, the width and length of the pit lane, and the angle of inclination of the corners.

There are also regulations on the safety-related facilities and spaces, specifically the protective walls and barriers. Concerning the barriers, Armco barriers, Tecpro barriers, concrete barriers, or tire walls must be erected due to the kinetic energy created when race cars collide.

More stringent standards are applied to spectator seats. A certain distance must be kept between the track and spectator seats and that distance may be further extended in consideration of the average passing speed in the section and the kinetic energy created as a result. Additionally, both the height and width of the catch fence are specified to protect the spectators.

A run-off area is required to give the drivers space to regain control of their speed when they drive off the track as well, and there are regulations on escape zones and escape roads to move drivers from an accident scene to a pit, drainage facilities, or other facilities to conduct racing. The regulations associated with circuit construction are so complex and detailed that it is impossible to list them all here.

FIA grades obtained in compliance with these complex regulations are not permanent, however. Each track must undergo periodic re-examination, and the grade may be revoked if it fails to pass or pay for the license.

Such complex and stringent circuit regulations ensure the dynamics and thrills unique to motorsports.

More recently, circuits have not only been used for racing, but also as cultural complexes. Sochi in Russia, Hockenheim in Germany, and Yas Marina in Abu Dhabi were designed such that sections of their tracks can be a stage like a concert hall. In particular, Yas Marina was designed to enable racing cars to pass underneath the hotel through the circuits bridge. This is a strategic design made to improve the profitability of the circuits.

Unlike the designs described previously, some circuits are completely closed off to the public. They hold no events, no performances, not even races. A leading example would be the Nardò Ring acquired by Porsche in 2012. Located in Nardò, Italy, the gigantic track visible from space forms an almost perfect circle. Its sole purpose is top speed testing. The only purpose of the 12.5km long banked circular circuit is to provide a dash straight ahead.

Throughout the day, these circuits are filled with the sounds of friction produced by tires. Unlike automakers that extensively conduct different sets of tests to measure the performance of the engines and transmission systems or to observe the reaction of the car body, endless tests are conducted here solely on tires.

This means tire companies have greater intellectual assets when it comes to driving experience.

By launching test tracks and improved standards and facilities, tire companies are adapting to changes as the demand on tires has become stricter and more complex. That is why Hankook Tire has newly built Asia's largest test track named Hankook TechnoRing.