TRANSPORTATION SYSTEMS are essential to large cities around the world, helping people get to work and school. At the same time, transit contributes to pollution and climate change and is the fourth-largest source of global greenhouse gas emissions—and growing.
Rema Hanna, the Jeffrey Cheah Professor of South-East Asia Studies at HKS, and Gabriel Kreindler, a Harvard assistant professor of economics, are leading a new multi-year Harvard-wide project to improve and decarbonize transportation in megacities in the global South, improving mobility while addressing climate change. As principal investigators for the urban mobility and climate change cluster at Harvard’s Salata Institute for Climate and Sustainability, Hanna and Kreindler will lead efforts by an interdisciplinary group of Harvard scholars to investigate how to decarbonize urban transit in developing countries—by, for instance, replacing conventional motorcycle engines with electric ones, measure and reduce co-pollutants, and help communities understand and adapt to climate shocks such as flooding and severe heat. “This project will devise innovative, sustainable transport solutions that balance economic benefits with reduced environmental impact,” Hanna says. The researchers will be working with policymakers in Jakarta and elsewhere in Indonesia to test and scale ideas that might have a positive impact on millions of city residents.
Improving Jakarta’s bus network
Hanna has long done work in the field of international development, looking at the role that mechanisms such as cash transfers can play in boosting growth, as well as issues related to improving transportation in developing countries. Before receiving funding from the Salata Institute to lead the new research cluster on climate and urban mobility, she and collaborators had already undertaken research to optimize the bus system in Jakarta, Indonesia, in cooperation with officials from that system, TransJakarta. Starting in 2018, Hanna and her team worked closely with TransJakarta leadership, bus dispatchers, and IT personnel, meeting on a near weekly basis to study and improve the bus system.
As Hanna and coauthors wrote in a VoxDev article, “This collaboration had real impacts for TransJakarta. In 2022, recognizing the untapped potential of its own data, TransJakarta implemented a new policy and improved infrastructure to better enforce how passengers use fare cards to tap in and tap out of buses, resulting in a 40% increase in the passenger tap out rate. Informed by the results of the study, TransJakarta leadership has expressed support for providing more reliable wait time information to passengers and continuing the expansion of its network. While projects like this take time and require intensive collaboration, they can have important impacts for transport policy and operations on the ground.”
Other analyses Hanna and coauthors conducted for TransJakarta revealed insights such as that people were less willing to wait longer at a bus stop than to have a longer bus ride. The researchers demonstrated how to design a network whose benefits would be equivalent to shaving an average of 23 minutes of travel time off every bus trip. The work Hanna is conducting in Indonesia could ultimately lead to a better experience for commuters and cleaner, more efficient transit.
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Banner image: An aerial view of traffic and buildings in Jakarta, Indonesia. Photo by Bay Ismoyo/AFP; portrait by Martha Stewart