While racing on foot, chariots, and beasts of burden such as horses is an ancient tradition, the modern conceptualization of racing is incredibly recent, with the earliest automobile races held soon after the invention of the automobile - primarily as reliability trials for the new machines.
Automobile racing only came into the public eye only fifty years ago with the first city-to-city race - in which the winner (and only competitor to successfully finish) clocked a mere six miles per hour, taking nearly a day and a half to finish the over two hundred mile track. Several competitions, both major and minor, occurred over the following decades, beginning to build up a dedicated following of motor fans.
Street racing began fifteen years ago, when a certain
set of miscreants drove early automobiles through the streets of
Sistu at the then-reckless speed of twelve miles per hour. (Notably, one professional runner saw them passing and decided to join the impromptu race, winning by all accounts.)
Three years ago, racing caught inter-dimensional attention with the longest race in history, circumnavigating the entire planet of
Veshiri (which is made possible by the density of islands) and passing through parts of several other worlds. Ten competitors took part, with only three finishing the race - which took an unprecedented one hundred and eighty three days. The Stenari R Racer (or Flying Teakettle as its fans often call it), manufactured by the
Stenari Motor Carriage Company and driven by a team from
Lidaidi, won the race by a margin of thirty two days. The event received front-page coverage in newspapers across not only the planet but the entire Council of Worlds, most notably leading to calls for improvements in roads (or even construction of them in the first place).

The largest spectator stadium in the entire Council of Worlds, the Dijua Motor Speedway, built in the new suburban city of Speedway on the northwestern coast of the Dijuan Continent, is a two and a half mile brick banked oval track designed specifically for automobile racing, including magical safety features designed to preserve life in the event of a wreck and to prevent automobiles from crashing into spectator areas, while not obstructing view. It has an astounding capacity of three hundred thousand permanent seats, with infield seating adding another hundred and fifty thousand potential spectators. It was constructed just last year and has already had such notable visitors as the Prince and Princess of Alea and the sitting Veshiri Empress.

Very recently, the racing fad has caught the imagination of a few reckless youths, who have modified personal airships, called steam skimmers colloquially, to reach tremendous and often dangerous speeds as they rocket through the air. Fortunately, such races are currently often held outside city limits, reducing the risks of crashes dramatically. However, the steam skimmers are far more dangerous than even the early automobile, with engines frequently failing or outright exploding under the stresses put on them.
Matthieu A.
So they are riding through worlds on old-looking cars like that ? It's pretty neat if that's the case, I really like the idea :]
Thanks! Not frequently, especially since most worlds don't have suitable roads yet, but on occasion, yes. The city of Sistu especially has established inter-world portals large enough for automobile traffic