This dataset details the ages of guideway elements for each applicable agency reporting to the National Transit Database in the 2022 and 2023 report years. Guideway elements include elements, structures, or facilities dedicated specifically to transit use, such as track, subway structures, tunnels, bridges, and propulsion power systems. NTD Data Tables organize and summarize data from the 2022 and 2023 National Transit Database in a manner that is more useful for quick reference and summary analysis. This dataset is based on the 2022 and 2023 Transit Way Mileage database files. In years 2015-2021, you can find this data in the "Track and Roadway" data table on NTD Program website, at https://transit.dot.gov/ntd/ntd-data. In versions of the data tables from before 2015, you can find data on vehicles in the file called "Transit Way Mileage - Rail Modes." If you have any other questions about this table, please contact the NTD Help Desk at NTDHelp@dot.gov.