* Interpret changes in median value with caution; some aspects of database have changed over time, and median value is affected by the number of metro areas reporting zeroes.
Years Available: 1991–2018
Permanent Link: http://data.sagepub.com/sagestats/7018
General Notes: *Median value gives the value for the "average" metro area for this metric, the 50th percentile of all metro areas reporting data. Data for all urbanized areas within a metro area. An urbanized area has at least 50,000 people with a population density of 1,000 or more per square mile at its core. There may be more than one distinct urbanized area in a metro area. **Layover time considered revenue time. Prior to 1999, it was ambiguous. SAGE used data from the original source to sum up values for multiple transit bodies in the same metro area.