Solo (also known as slalom) originated in the US. In 2002, it was pioneered in the UK by Bristol Motor Club. The second event was run again by Bristol Motor Club in May 2003, which started a landslide of other motorclubs running Solo events.

Solo is a test of car control, with speeds between that of Autotesting and Sprinting. Unlike Autotesting, no reversing is involved, although unlike Sprinting, the handbrake turn is regularly used. Cars compete one at a time on a course laid out with marker cones. Cars are timed over the length of the course, usually by handheld stopwatch.

Solo is designed as a cheap motorsport event to compete in. Cars are usually required to be road-legal, and driven to the event. The cost of marshalls is negated by the competitors taking turns to marshall in order to have their results published. Competitors are split into three groups who are either marshalling, preparing to compete, or competing. The low speeds involved negate the need for a rescue crew.

The event consists of a number of tests (usually between 3 and 6) run either two or three times. Only the fastest runs on each test count towards the aggregate time. In addition to the time taken, penalties are awarded for hitting marker cones and taking a wrong turn. The competitor with the lowest aggregate time wins the event.