The 4 x 400 metre relay, sometimes known as the long relay, is an athletics track event in which teams of four runners go 400 metres, or one circuit. It is usually the last event of a track meet. The opening 500 metres of top-level competitions are run in lanes. At lower levels, all runners typically start at the same time from a single start line on the track. The 4 x 400 metre relay is the most popular individual distance on the track. Teams can change order without losing momentum by passing the baton between members of the team; this is possible because each runner covers the same distance in the same amount of time. A team can also choose not to pass the baton if they want to keep their fastest runner available for a personal best or a winning effort. There is no rule that states how many times a relay team must complete the course. Some teams will finish in less than 44 seconds while others may take more than 1:20. In most cases, the number of laps is either noted by a timer or estimated by spectators. The average speed over the entire course is about 200 meters per minute, so each lap lasts about 0.5 minutes. In terms of distance, it is recommended that you divide the total length of the field (in meters) by 0.44 to get the number of laps.