The joker lap is a traditional feature on rallycross circuits.
Each course is equipped with two routes: the main route, and the joker lap route, which each driver must only take once per race. The GRC joker lap route typically shortens the length of the track significantly (while in the FIA World Rallycross Championship the JL detour is longer than the main route, to slow the cars down for a minimum of two seconds), forcing a driver to make strategic decisions about when to take it. On one hand, taking it on the first lap allows a driver to get it over with; on the other, waiting until the end of the race can allow a driver to gain positions before the finish. Depending on venue, the joker lap route may have additional obstacles which significantly slow the cars thus making the main route faster.