About this Data
1. Fall 2016 Average MTA Bus Speed: This data is reported to be aggregate data for all MTA core bus service, and was reported to the Transportation Alliance by the MTA by email.
2. Average Speed by Mode: This data is compiled from the data reported each year to the National Transit Database, and is reported each year by the American Public Transit Association (APTA) in its annual Public Transportation Factbook.
3. Average Speed by Operating Segment: This data was calculated by the Transportation Alliance from MTA's GTFS data. Transportation Alliance analyzed three CityLink lines, the Lime, Red, and Blue by operating segments during the AM peak time (specifically, between approximately 8:00AM and 9:00AM on a Wednesday). Operating segments were determined by considering development patterns (attached versus detached housing), zoning designations (the Downtown district), and roadway functional classification or other roadway designation (principal versus minor arterial or collector, whether the road is designated a state or federal highway).
What We Know
Speed and Travel Time are Different, but Related
As transportation consultant Jarrett Walker will remind us, the speed of a transit vehicle is often not the most important element in whether service is working for riders. Because frequency and reliability affect the time riders wait for transit vehicles, those elements may be more likely to affect your level of satisfaction with service, or even how long your journey is. However, vehicle speed does matter because it cannot be ignored as an essential component of travel time, and therefore has a direct impact on access, for example, when access is defined within a total travel time boundary such as 30, 45, or 60 minutes.
Focusing in on vehicle speed leads us to ask how the physical design of the roadway can improve transit vehicle speeds, in addition to how operational policies can do the same. The difference in speed between buses and streetcars as opposed to light rail or heavy rail comes from building infrastructure that allows transit vehicles to move more efficiently through urban places, as well as policies that affect station dwell time.
For example, bus bulbs permit a bus to remain in a single travel lane instead of having to pull over to the curb to access a bus stop, only to have to merge back into traffic to proceed along the route. Traffic signal priority (TSP), which involves installing hardware on transit vehicles and signals that reduce the time vehicles wait at lights also improves transit vehicle speed. Policies like permitting all-door boarding and off-board fare payment also reduce dwell time, specifically for buses, since most rail vehicles already utilize these approaches.
MTA Does Not Currently Report Speed
While MTA can calculate average transit vehicle speed if necessary, MTA does not make a practice of reporting average speeds to the general public. This data is reported from time to time in planning documents, or by MTA staff upon request by a stakeholder.
However, MTA does make available its GTFS and GTFS-RT feeds, from which scheduled and actual speed can be calculated by third parties with the means to analyze this data.
Interventions that Improve Speed Usually Improve Reliability, Too
The kind of improvements that improve transit vehicle speed, like TSP and all-door boarding, usually also improve reliability, because they make the movement of the bus more predictable and less subject to surprise delays. Bus "bunching", the main issue affecting bus reliability (besides equipment or personnel issues), is caused by a "positive feedback loop" that typically begins with a small delay that then is magnified over time. Efforts to improve speed usually also address sources of these delays.
What We Need
Real-time, route specific data
MTA is currently working on procuring real-time GPS hardware for its buses. When this hardware becomes fully available, third parties will be able to calculate bus speed by accessing the GTFS-RT data, similarly to how the advocates and university students in NYC were able to create this website from raw data for NYC's buses.
Data that Identifies Problem Areas
However, beyond simply making raw data available, from which third parties can generate their own informational and advocacy tools, we want to know that MTA is also focusing in on average speed for different segments of its routes and targeting improvements. MTA did this when it installed downtown bus-only lanes to increase bus speeds through the region's biggest transportation bottlekneck, downtown Baltimore, or when it selected key corridors on which to install transit signal priority. However, MTA is just getting started with its program to make targeted improvements that improve bus speed.