Olympic tracks in the early 20th century were of other lengths. Each lane of the track could (by IAAF rules should) be as wide as 122 cm (4.00 ft),[1] though the majority of American tracks are built to NFHS high school specifications that allow smaller lanes.[2] The IAAF also specifies a preferred radius for the turns at 37 metres, but allows a range. Major international level meets are conducted and world records are allowed to be set on tracks that are not exactly 37 metres, but do fall in the range.