How does bus lane enforcement improve travel times?
This is based on a presentation I gave during Baltimore Neighborhood Indicators Alliance Data Day.
In 2018, the Maryland Transit Administration partnered with Swiftly, a platform that uses GPS data to do deep analytics on transit system performance. Location data provides a mountain of data, including bus location, speed, arrival time, on-time performance, headway, route, direction, and many others. The Swiftly data underpins the Transit App and has been a critical tool for the planning division as they have worked to improve the system’s on-time performance.
The MTA is the only one that has access to the private dashboard with historical data and powerful tools to slice and dice the mountain of data to answer various questions, which is where Transit Trak comes in. Transit Trak is an open-source project I wrote with three other people during the Baltimore Hackathon in March 2019 that collects historical MTA data and attempts to provide a similar dashboard like the one the MTA has.
Speed Data
Because of the course level of collection Transit Trak does, speed data is an imprecise metric, but does show important trends. A popular transportation Facebook group, Baltimore Transit, had a discussion about traffic and the Centre St bike lane. The OP indicated that the bike lane was causing traffic backups, and the thread became heated.
In fact, there were people who jumped in to say that the cause of the traffic backup was obviously Flowermart, as this post was from early May.
There is not publicly available speed data for that corridor, and the Transit Trak data does not show a before-and-after, so we need to extrapolate the data a bit.
The speed data shows a dramatic slowdown between MLK and Guilford Ave, which could support the theory that bike lanes cause traffic jams.
While the data is powerful, the story is more complicated. In fact, an MTA bus operator, Patrick Parents, wrote a blog post about the issue. He identifies a few issues, such as bad light synchronization, 60 second north/south light cycles, cars turning right on red and blocking their ability to get through the intersection, and the large number of people who board the bus in that corridor.
Potential fixes could involve ‘no right on red’ signs and shortening the light signal on the north/south streets.
Bus Lane Enforcement
Charles St has a peak hour bus lane from 4–6 pm, roughly between the Mount Washington Monument and Penn Station. Anecdotal reports from Twitter showed that cars were regularly parking in that lane with impunity.
I sent them a question about enforcement in mid-May about on that corridor but did not hear anything. Then, I started seeing pictures popping up in my Twitter feed. First, on Friday, June 7:
Then one on Monday, June 10.
Further reports showed that the enforcement continued on June 11 and June 13th.
And the ultimate picture of beauty on June 19.
But by June 26, the enforcement surge seemed to have ended.
So, what does the data say about such a surge? From April 1 until July 4, when I gave this presentation, 8 of the top 10 days for bus speed in the effected corridor were during the surge.
Looking at it today, 7 of the top 10 days were during that surge, with the other days being May 16, August 12, and the Monday after the 4th of July.
This tells us that enforcement is a critical part of an effective bus lane. The big dip right after the enforcement ends might also indicate that a lightly enforced lane is even worse than one that is not enforced at all, potentially because the bus is forced to pull into and out of the lane more frequently than if the lane is full of parked cars.
