This new arrangement also made it simpler for the crew to "wave off" an unsatisfactory attempt already in progress. At any time during the four-lap run, if the crew was dissatisfied with the performance, they could wave a yellow flag, and officials would immediately abort the run. Crews could now wave off a run without needing input from, or conveying the message to, the driver out on the track. Previously the only way to wave off a run was to pull into the pits. Typically, crew members would use hand-held stopwatches and clock their car from a reference point in turn four. That would give them enough time to estimate their forthcoming lap time, and decide whether to abort the run before the car crossed the start/finish line. Furthermore, the rules made it clear that the instant the yellow flag was waved by the crew, the run was aborted, irrespective of the position of the car out on the track. If the car continued down the mainstretch, it would not matter if he/she proceeded to cross the finish line. Previously, if a car physically crossed the finish line, the run counted and was locked in, even if the team was intending to wave off the run. That situation made for some precarious maneuvers to the pit lane or to cars stopping out on the track to avoid crossing the finish line and 'locking in' the undesirable qualifying time.