The encyclopedia · Strategy & Leadership · Operational decision · 2017–2019
Boston cut 50 school buses, saving $5M a year, by solving routes and start times together
MIT and Boston Public Schools jointly optimized bus routes and school start times, saving $5M a year and cutting 50 buses.
Boston Public Schools
the move
Maintaining a bus fleet is a major cost for US school districts, and many spread start times to reuse buses between schools. But that reassignment is done by hand, and the resulting early high-school starts harm student health.
MIT researchers, with Boston Public Schools, built the first algorithm to optimize bus routing and bell time assignment jointly. It decomposes the routing problem, solves subproblems with mixed-integer optimization, and uses that to price out what each start time would cost.
The method cut a process that took 10 people more than 3,000 hours to one that runs in about 30 minutes, while making the start-time tradeoffs — cost, equity, health — explicit choices for the district.
why it works
- It solved one joint problem instead of guessing at two separately, so buses and times reinforced each other.
- A transport-cost proxy made the start-time decision a solvable optimization rather than a hunch.
- It made student-health considerations an explicit objective, not an afterthought.
- Running in 30 minutes let the district explore options instead of committing to one.
what transfers
Two decisions people take in isolation — school start time and bus routing — are one cost problem; solve them together and the fleet shrinks, the budget frees up, and students get later mornings.
what came after
The algorithm led to $5 million in yearly savings and maintained service quality despite a 50-bus fleet reduction. In December 2017 the Boston School Committee unanimously approved the first school start-time reform in thirty years, moving to later middle- and high-school starts, and the work became a 2019 INFORMS Edelman finalist.
references
- New approach to optimizing school bus routes and start times reduces bus fleet and enables reinvestment in schools
- From School Buses to Start Times: Driving Policy With Optimization
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