In 2002, the ATC approved a set of six targets and indicators to measure improvements over time in performance of the interstate rail track. Early reports against the indicators were derived entirely from track managers' (below rail) datasets. An ARA survey of train operators (above rail)reporting on key performance indicators showed that results from track managers' datasets were, for some indicators, inconsistent with results based on rail operators' data. There are distinct reporting methodologies between above and below rail.