Now Trending: Data Dashboard 2.0
When we introduced the TransitMatters Data Dashboard last August, we were thrilled to offer a new tool for exploring MBTA rail performance data. In our original release post, we outlined how the dashboard allows our community to view travel times, time between trains (headways), and time spent at stations (dwell times) for the Red, Blue, Orange, and Green Lines for any day back to January 15, 2016.
We're proud to announce that we've upgraded our Data Dashboard to support viewing aggregated data to visualize trends over as many as eight months. You’re now able to select a date range with the “Range…” button in the toolbar, making it possible to view daily medians & interquartile ranges for travel times, headways, and dwell times over extended periods—no longer just a single day at a time.
Selecting the Range option enables start and end date fields, allowing you to input a time range for which you would like to generate charts. The previously available single-day view is still there—just leave the end date blank.
The following charts show how travel time and headway metrics from Revere Beach to Aquarium have changed from January to April this year. Each black dot is the median value for that metric on that day, and the shaded region is the range between the 25th and 75th percentiles, also known as the interquartile range. A larger shaded region around a point indicates higher variability in that metric on that day.
Browsing these trends over time is useful for transit advocacy for a variety of reasons. One key area of discussion is rail slow zones. The MBTA sometimes introduces these reduced “speed limits” on sections of track due to maintenance or deterioration. Trends in performance metrics expose when these slow zones are introduced or fixed by the agency. For example, a slow zone between Back Bay and Tufts Medical Center stations on the Orange Line was fixed over a series of months in Fall 2020:
Another slow zone between Community College and North Station existed for just a single month, December 14, 2020 - January 13, 2021:
Trends can also expose effects of the COVID-19 pandemic. For example, on the Green Line C branch, travel times fell as much as 25% as road traffic decreased and dwell times decreased due to fewer riders.
The TransitMatters Labs team is looking forward to learning what trends you can find in subway performance data. Go explore yourself! Each chart has a unique link, enabling you to easily share your finds with others interested in this data.
We appreciate your questions or feedback; we’re reachable at labs@transitmatters.org. You can also give a shout out with your findings to some of the team members who worked on this project on Twitter:
Preston Mueller (@mathcolo)
Austin Paul (@ajp5678)
Chris Friend (@friendchristoph)