In public transportation, ridership refers to the number of people using a transit service.^[1] It is often summed or otherwise aggregated over some period of time for a given service or set of services and used as a benchmark of success or usefulness. Common statistics include the number of people served by an entire transit system in a year and the number of people served each day by a single transit line.

This article needs additional citations for verification. (May 2023)

The concept should not be confused with the maximum capacity of a particular vehicle or transit line.

• Crush load – High passenger vehicle occupancy leading to crushing
• Environmental impact of transport
• Headway – Distance between vehicles in a transit system measured in time or space
• Route capacity – Maximum occupancy of a route in a given time
• Passenger load factor – Capacity utilization of public transport
• Passengers per hour per direction – Measure of passenger capacity of a transportation network
• Public transport accessibility level