Ridership on the T

We collect data on ridership for the bus, subway, Commuter Rail, ferry, and The RIDE. Ridership means the number of people who ride a system of public transportation. We count every time a rider boards a vehicle on weekdays and then calculate the total at the end of each month.

How We Measure Ridership

To measure ridership, we count each time a rider boards a vehicle. We count individual rides so we don’t leave out trips taken by riders who make one or more transfers.

For example, if a rider is on their way to work and has to transfer from the bus to the Green Line to the Red Line, we count that as three rides.

Counting Individual Rides

Below is how we calculate the total number of rides taken on each mode. 

Bus and Subway

There are two main sources of passenger data:

• Automated passenger counters (APCs)
• Automated fare collection (AFC) system

APCs use infrared beams and other technologies to count all riders who enter vehicles, so we use those for ridership when possible. The AFC system counts CharlieCard and ticket taps.

For services where we do not have significant APC coverage, we use estimates based on data from the AFC system. Those estimates are adjusted to account for riders who do not interact with the fare box and for transfers that happen behind the fare gates.

We also manually count rides at various times and places to check against our automatically collected data.

Commuter Rail

We combine conductor counts and manual counts from terminal stations.