Service Reliability
We can’t improve service reliability without first accurately measuring it. To measure how reliable our service is for riders, we use different metrics for each mode. We use different metrics for each because they don't operate the same. These metrics also reflect how riders experience them.
As of summer 2024, the MBTA is drafting an updated Service Delivery Policy (SDP). This will introduce new definitions and standards used to calculate reliability data. The Service Reliability dashboard will return to reflect these updated standards. Check back here for updates.
How We Measure Subway Trip Time
Trip time is how many minutes it takes for a rider to travel from one end of a subway line to the other. Each line travels in two directions and has separate trip times for each direction.
To measure trip time, first, we calculate the daily median trip time for the Orange and Blue lines in both directions, and each branch in both directions on the Green, Red, and Mattapan Lines. Then, we calculate the average of both medians from each of those lines to find each line’s daily average trip time. Finally, we calculate a seven-day average trip time for each line, each day. To do that, we find the average of the seven most recent daily average trip times.
As of Summer 2024, trip time data is available for all lines.
