The Massachusetts Bay Transportation Authority moves hundreds of thousands of people across Greater Boston each day—thanks to a vast system of buses, trains, and ferries that depends on coordination among thousands of employees.
In this storied transit system, history runs deep: The Green Line still passes through the country’s oldest subway tunnels, built beneath the Boston Common at the end of the 19th century. Yet the MBTA is remarkably willing to explore new approaches, too. That’s thanks in large part to a trio of MIT alumni: Katie Choe ’98, SM ’00; Melissa Dullea ’00; and Karti Subramanian, MBA ’17. Together, they’ve been helping redefine what innovation looks like in one of the nation’s longest-running transit systems.
Choe in particular has been at the center of this push as the agency’s chief of staff since 2023, a position in which she took the lead in revamping organizational culture. She wrapped up her tenure at the T to become CEO of Virginia Railway Express (VRE) in January, but before leaving, she spoke to MIT Alumni News extensively about her role. Describing it as “owning everything and nothing at the same time,” Choe explained: “I’m here to make things happen. I find places where we have a sticky organizational knot that needs to be untied.”
Dullea, the MBTA’s senior director of service planning, is in charge of the team responsible for planning and scheduling every bus route in the system as well as the Red, Orange, Green, and Blue Lines. Her group also determines where buses operate and adapts both train and bus service patterns as the region changes.
Subramanian, the MBTA’s senior director of rider tools, leads a team that manages the agency’s digital ecosystem: the website, real-time signage, and the MBTA Go app, which offers riders live transit information—including arrival times, vehicle tracking, and closure updates—for buses, trains, and ferries.
Innovation, in Choe’s view, is a practical requirement in a system whose infrastructure dates back to the opening of the Tremont Street subway in 1897. There are old assets to maintain and modern expectations to meet, all with public resources that never stretch far enough. For years, she says, the instinct was to plan endlessly in hopes of pleasing everyone, only to end up pleasing no one because little actually moved forward. Resources were consumed by process rather than progress.
The way out of that cycle was to rethink how projects are delivered, structure contracts differently, and streamline operations by relying more on in-house expertise. The result, she says, is an increasingly “can-do” culture that focuses less on drafting plans and more on producing results, a change she sees as essential to maintaining service reliability and supporting the region’s economic mobility. And while aging Red Line cars, which perform poorly in extreme cold, will continue to pose challenges until new cars replace them and planned service disruptions for needed repairs on all subway lines are ongoing, service is improving overall. Since spring 2024, the number of scheduled weekday trips on the Red, Orange, and Blue Lines has climbed steadily, thanks to extensive track repairs, new operating procedures, and the addition of more railcars.
The new innovation mindset—including the emphasis on faster, more efficient project delivery and cross-department collaboration—is likely to shape the MBTA for years to come.
Innovation grounded in public service
Choe has spent her career in the public sector, a choice she attributes partly to a sense of responsibility cultivated at MIT. “The big differentiator at MIT is that when you graduate, you graduate with an expectation that you are going to change the world,” she says.
After more than six years as chief engineer and director of construction management at Boston’s Department of Public Works, Choe joined the MBTA in early 2020. In 2023, she launched the Innovation Hub, an initiative that spotlights and promotes internal improvements, as part of the quest to deliver the best possible service to riders on the constrained budget of a public agency. “We need to constantly be thinking about how we can do that better,” she says. “How do we do it more efficiently? How do we actually keep our costs low, find new ways of doing things so that we can provide that service better for all of our riders?”
She adds, “When people come to me with an idea, I try really hard to support them with moving it forward. That’s the innovative culture that we’re trying to instill.”
The Innovation Hub gives employees a place to raise problems or suggest ideas and connects them with the partners and support needed to turn concepts into real projects. It also celebrates workforce creativity, hosting an annual Innovation Expo—a showcase similar to a poster session (“It’s essentially a science fair,” Choe says) that highlights projects from throughout the agency.
“The energy that was in the room was just palpable,” she says of the first Innovation Expo, held in the summer of 2024. It showcased 34 completed projects, from maintenance upgrades and redesigned processes to data tools that streamlined field operations. The projects led to faster hiring, better safety practices, and more agile planning for disruptions—and many improved the employee experience as much as the rider experience. Choe sees the two as inseparable. “The better our employees can perform, the more we take care of them, the better the service to our riders is,” she says.
“We should consider it normal and necessary for a transit agency to provide really accurate, really accessible, real-time information to its riders.”
Karti Subramanian, MBA ’17
She also helped oversee a welcome improvement to the systemwide discount program that low-income passengers can use for all forms of transit, from the commuter rail to The Ride, the door-to-door rideshare program for people with disabilities. The MBTA built an efficient system that verifies riders’ eligibility through existing public benefit programs, allowing approvals in about 30 seconds. Other agencies have since asked to learn how it works.
Meanwhile, Choe devoted considerable energy to mentoring. She helped lead programs to support women in the agency, met with new employee cohorts, and advised early-career staff on navigating large institutions.
“I look for people who are willing to take risks and to put themselves out there,” she says. When she looks back at the things that have advanced her most in her own career, she adds, it’s “those moments that I’ve taken those risks.” For example, in 2022 she was asked to build and lead a team to transform the MBTA in response to findings from a Federal Transit Administration safety management inspection—and given 24 hours to decide whether she would. “It thrust me into the public spotlight with no room for failure,” she says. “The exposure to parts of the organization that I had had little interaction with and the forced fast learning curve set me up for the success of both the chief of staff role and my new position at VRE.”
Rethinking the bus network
Route planning and scheduling are at the heart of the rider experience. And in Dullea’s telling, this work is a complicated puzzle with many pieces.
First, the planners decide where bus routes run, how frequently buses and trains arrive, and where bus stops are located. Then the schedulers turn those plans into reality, constructing work assignments that keep service as dependable as possible within the constraints of collective bargaining agreements, rest rules, and bus availability. “The service planners are the architects of the schedules,” she says. “The schedulers are the builders.”
Dullea’s path to transit began at MIT, where she was introduced to the MBTA’s planning work, including efforts to relocate the Orange Line in the 1980s and projects like the Urban Ring, an efficient rapid-bus system that was once proposed as a way of connecting the outer “spokes” of MBTA lines to reduce congestion downtown and link Greater Boston’s booming residential and commercial areas. This sparked a growing interest in the field and ultimately led her to write her undergraduate thesis on the MBTA assessment formula, which determines how much each community in the service district contributes annually to the system’s operating budget. “I was like, ‘Wow, you can have a career in transit. This is amazing,’” she says.
She joined the MBTA as a junior planner soon after graduating and now co-leads one of the agency’s largest planning efforts: the Bus Network Redesign (BNR), part of the broader Better Bus Project.
“We’re not in an industry where you can move fast and break things. We want to have a focus on improving the customer experience.”
Melissa Dullea ’00
The redesign began with a fundamental question: How can the bus network reflect where people need to go today? To find out, her team used anonymized cell-phone data to map the patterns of people’s travel by all modes—including public transit, driving, walking, and biking—and then weighted the data to prioritize communities that rely more on transit. They combined algorithmic modeling with human judgment, narrowing an estimated 14 million computer-generated corridors—potential pathways where demand suggested a bus route could run—into a workable network that would better meet observed travel demand.
“We wanted to make sure that the bus network would be relevant for how people travel now, and not just how we’ve always done things,” she says.
And their methodology allowed them to improve upon their previous practice of checking for discrimination at the end of planning. “We were able to lead with equity,” she says.
The final plan nearly doubled the number of routes where buses run every 15 minutes or less and expanded coverage in Chelsea, Everett, Malden, and Revere. The Commonwealth recently recognized the project with an equity award.
When the pandemic led to a shortage of bus drivers, implementation paused. But Dullea’s team and others in the agency used the setback to rethink hiring, training, and job quality.
“We’ve been working to build back,” Dullea says. The ability to hire committed drivers—and keep them on the job—depends on providing a good work environment. “We’ve been doing a lot of work on just making the experience of being an operator better,” she says.
For example, Dullea’s team helped redesign schedules that often saddled operators with long unpaid breaks in the middle of the day. By hiring part-timers who work a single peak period without a break, the T has reduced the average unpaid break time by half.
Dullea’s MIT training prepared her for the challenge, teaching her to analyze complicated systems and follow her intellectual curiosity.
“When I was an undergrad, I just realized I loved cities,” she says. “And I was like, ‘How can I turn that love for the urban environment into a career and solve real-world problems that can help people?’”
Building a better digital front door
Subramanian founded a software company serving nonprofits before arriving at MIT for graduate school. His transition to government work—and eventually to the MBTA—was driven by a belief in public service and in government as a force for good.
“I really wanted to serve the public sector in some way,” he says.
Subramanian resists calling his work “innovation.” He sees it instead as delivering the basic information riders should expect from a modern transit system.
“We should consider it normal and necessary for a transit agency to provide really accurate, really accessible, real-time information to its riders,” he says. “Doing it might be new and different and require new ways of working.”
At a large agency, achieving that goal is far from simple. To start, Subramanian embedded team members in the operations groups managing more than 170 bus routes and the four subway lines with an eye to building better dispatching tools. This work also created data feeds that his team made publicly available—and used to create the MBTA Go app. But before building it, they asked what value it could add in a world where riders already use Google Maps and third-party apps like Transit. The answer was operational insight.
“We know more about MBTA operations than Google Maps does,” he says. “So we can publish insight into what’s happening that a third party like the Transit app that’s designing for 200 cities at a time, or Google Maps that’s designing for 200,000 cities at a time, will never think to show.”
A key area where that kind of information pays off is accessibility—a defining focus for Subramanian, whose son has cerebral palsy. He’s partnered with the MBTA’s System-Wide Accessibility Department to create the Accessible Technology Program, which brings riders with disabilities into the design process.
His team conducts extensive user research, interviewing and riding alongside people who use mobility devices, depend on elevators, or have low vision, to understand the barriers they encounter on trains and buses and in stations. Through this hands-on approach, Subramanian’s team gains direct insight into the everyday obstacles riders face and how small design decisions can create or remove them.
“For me, this twin personal/professional journey has been probably the most wonderful part of this job,” he says. “An amazing amount of work and leadership has gone into making the MBTA one of the—if not the—most accessible transit systems in the US.”
The work is grounded in long institutional history. A landmark 2006 settlement under the Americans with Disabilities Act created a dedicated accessibility office within the MBTA, which continues to drive systemwide improvements.
Subramanian attributes his approach in part to lessons from MIT about the public origins of much modern technology. “So much of the kind of now very tech-forward innovation … came from early government R&D,” he says.
To him, that lesson underscores the value of public service. “To do foundational things right in government actually is very high leverage,” he says, adding that it’s currently dramatically undervalued and underappreciated.
Improving within constraints
Change at the MBTA unfolds within a highly regulated, risk-averse setting.
“Innovation takes some acceptance of failure, and that’s hard in a public environment,” Choe says. “We’re aspirational but not reckless.”
Most ideas under consideration, whether they’re crowding indicators on the Orange Line or wayfinding tools for riders with low vision, get tested in limited, clearly labeled trials.
Dullea echoes the careful balance required in planning. “We’re not in an industry where you can move fast and break things,” she says. “We’re trying not to break things. We want to have a focus on improving the customer experience.”
For Subramanian, the most significant challenges are often internal. His team works closely with operations groups, embedding technologists in bus garages and rail divisions to understand daily barriers. This partnership led to a mobile dispatching tool that replaced clipboards and a single-channel radio for managing nearly a thousand buses.
It has also helped his group become deeply integrated across the agency, forming an increasingly connected, data-driven operation. “We’re really proud of the extent to which we have built trust within the organization to bring this product way of thinking to a different set of problems,” he says.
Advancing the economic engine of Greater Boston
Choe sees the transit agency as a public service and a key support for opportunity across the region.
“Many of our riders rely on the MBTA to get to their jobs, to get to their health-care appointments, to get to critical areas of their life,” she says. “If we cannot provide those services, then we’ve really shut them off from that economic mobility.”
That responsibility directed her leadership. “Every single person is impacted on a daily basis by the work that I do,” she said in October. “Every improvement that I make is making someone’s life better, and that knowledge sits very deeply in my heart.”
Despite the challenges, she remains optimistic about the MBTA’s future.
“We have so much buy-in right now from the governor and the legislature,” she said. “It’s allowing us to do things in a little bit bolder manner than what we have done in the past. So I think our future is really bright.”
A culture of collaboration and aspiration
The MBTA also benefited from a partnership that spanned more than a decade with MIT’s Transit Lab, which supported the agency’s work with data analysis and service evaluation. Researchers at the Transit Lab helped the T interpret CharlieCard data to understand travel patterns and contributed the analytical framework for the agency’s Service Delivery Policy, which defines how the MBTA measures its own performance.
Following the productive collaboration with the MIT Transit Lab, Choe sees potential to deepen the agency’s connection with the Institute if the MBTA joins the MIT Transit Research Consortium. Run by the Transit Lab and the MIT Mobility Initiative, the consortium includes both US and non-US transit agencies, and it offers members workshops as well as insights into MIT’s ongoing transit research. “There’s an opportunity there to figure out how to bridge the gap between amazing research work that’s happening and the on-the-ground applications of that research,” she says.
At the moment, Choe says, the MBTA is investing in electrification and digital infrastructure and exploring AI-assisted maintenance—and sustaining a culture of openness to change will be key. The Innovation Hub is dividing into two branches, one supporting employee-driven ideas and another exploring emerging technologies like AI and autonomous systems.
“People are already interested in this,” she says. “So why are we not harnessing that excitement?”
Her work aimed to continue building a collaborative, curious workplace where new ideas translate into improved service. As she put it, “I want to work in an environment and a culture that is collaborative and aspirational all the time.”
Her colleagues share that goal: to keep the MBTA evolving, grounded in public service, and positioned to deliver a modern system for Greater Boston.
“It’s not just that we have a plan on the shelf that says this is what we want to do,” she says. “It is what are we doing right now to build toward this best-in-class, amazing, modernized, incredible system that serves the Commonwealth of Massachusetts.”
