Algorithms are invading transportation in a variety of ways beyond the flashy chase for self-driving cars. A new report shows that in Boston, an algorithm that was first implemented in 2017 to increase the efficiency of school bus driving routes has worked with tremendous success.
Algorithms are already in many driving decisions thanks to services like Google Maps. But busing routes are considerably more complex than many others. As documented in a report by Emma Coleman of Route Fifty, a publication focused on technology at the state and local level, Boston Public School (BPS) had exorbitantly high transportation costs of "$2,000 per student per year, representing 10 [percent] of the district’s budget." And for all that, BPS' buses were still inconsistent in when they actually showed up to many students' homes.
So BPS decided to field a competition to find the best possible algorithm that could tackle the problems. The eventual winners were nearby: Arthur Delarue and Sebastien Martin, doctoral students at MIT, who called their algorithm "Quantum."
Busing represented a challenge to the two, and the car-focused Google Maps wouldn't be much help. The BPS system delivered students who live in over 20 various zip codes to 220 schools. And then, the schools all had varying start times ranging from 7:15 to 9:30 a.m, so buses might have to touch base at multiple schools for student drop off. Around 5,000 students had special needs, demanding house drop-off and pick-ups. And being late wasn't an option.
"First we take into account all the average traffic, and then we add some slack to make sure that even if things go wrong, we still have some time," Martin told Boston area radio station WBUR at the time of the announcement. On that of that, he said, "we have a second problem. How to choose the solution for each school so that we have the best routes overall."
Trying to calculate all the options, Delarue tells Route Fifty, made a “number of solutions so large that you can’t even enumerate it."
But John Hanlon, director of operations for BPS, had faith in the project. "It takes a team of six to eight individuals about four weeks to complete the routing [each year]," he told WBUR. "The Quantum team solution can do all that in 30 minutes."
There was some local resistance. "Machines don't make routes—humans make routes," said Andre Francois, president of the local bus drivers' union, according to WBUR. "Machines send you to one-ways, dead-ends. These things never work!"
But it wasn't Quantum alone making the decisions. Delarue said at the time that "every single route will have been checked by people with years or even decades of experience."
Three years later, it appears that Hanlon's trust was well-placed. Route Fifty reports that for the 2017-18 school year, within a half hour, "the algorithm created a system-level route map that was 20 [percent] more efficient than the ones done by hand." Testing during the summer of 2017 allowed the system "to eliminate 50 buses, an 8 [percent] drop. Buses drove 1 million fewer miles that year and cut 20,000 pounds of carbon dioxide emissions per day."
As a result of the savings, the district was able to reinvest $5 million saved back into classroom initiatives.
The Quantum team says the collaboration between city and algorithm was crucial to the success of the project.
“The work of route managers in communicating with stakeholders such as drivers, principals, parents, and students is invaluable and cannot be replaced,” Delarue tells Route Fifty now. “But in what order stops should be visited, and how that route gets designed can’t be solved efficiently by humans. That’s where we add value.”
Boston schools haven't gone completely algorithmic just yet. Last year, an algorithm-based study failed to offer a plan for better school racial integration, and parents are still resistant to an algorithms that could alter high school start times. But still, when one is able to work, it would appear that everyone wins.
Source: https://www.popularmechanics.com/technology/infrastructure/a28689713/algorithm-boston-buses/
