In drag racing, two vehicles usually compete side by side in one race.
A typical drag race is a head-to-head contest between vehicles in parallel lanes. Both start from a standstill, launch when the starting system signals, and accelerate along a short, straight course. The winner is the first vehicle to cross the finish line, making the format naturally suited to two competitors racing directly against each other.
The most familiar distance is a quarter mile, although 1,000 feet has become standard for some professional Top Fuel and Funny Car events, and an eighth mile is also common in some forms of racing. Electronic timing and speed sensors record elapsed time and terminal speed.
Two-vehicle eliminations are especially important in organized drag racing: winners advance through brackets until a final determines the event winner. Some events can use unusual formats or exhibition runs, but “usually two” is the standard answer for the conventional race format.