Williams said it is tempting to view traffic deaths as a “cost of doing business” for the fast, convenient transportation vehicles offer. But the promising results gained by seat-belt laws, the designated-driver campaign (pioneered at the Harvard T.H. Chan School’s Center for Health Communication) and Sweden’s Vision Zero program, which has halved the rate of traffic fatalities and is being replicated in other countries, show that road-related deaths and injuries often don’t have to happen and shouldn’t be accepted.

Traffic accidents cost society greatly, Williams said. More people die from crashes than from either AIDS or malaria. In 2015, traffic fatalities were the 10th leading cause of death worldwide and the leading cause among 15- to 29-year-olds. Without new steps to reduce it, projections are that by 2030 it could be the seventh-leading cause of death worldwide, Williams said.

Accidents impose an economic toll as well, Williams said, costing most countries as much as 3 percent of their gross domestic product. And, as with many global health disparities, the burden falls disproportionately outside of the industrialized world, with 90 percent of fatalities occurring in low- and middle-income countries, even though they have just half the world’s vehicles.

“It’s hard to imagine a public health challenge of greater magnitude and geographical range than that of road traffic injuries,” Williams said. “The toll of road traffic injuries is staggering.”

Speakers at the event highlighted several steps countries can take to make their roads safer. Helmet laws would make a big difference in places where motorcycles are widely used as a family’s only transportation. Lower speed limits, seat-belt laws, and tough restrictions against drunk driving are also effective, as are improved emergency care and reduced response times, as well as engineering solutions that make vehicles and roadways safer.

For example, Tewari spoke of removing a poorly designed bridge pillar and concrete roadside flower pots on the Mumbai to Pune highway that had been involved in past crashes. Overall, Tewari said, their investigation of the roadway revealed 2,150 engineering errors. His foundation fixed 922 of them last year, he said, and in 2017 fatalities on the road dropped 30 percent, while those involving infrastructure fell 78 percent.

Overall, the speakers advocated an evidence-based approach, where analysis of the causes of traffic accidents in various locations can lead to effective solutions.

“This problem of road traffic injuries is massive. It feels complicated because it is complicated,” said Harvard Global Health Institute Director Ashish Jha, the K.T. Li Professor of Global Health. “We can take bits of it and pieces of it … and make progress on it in ways that dramatically reduce the suffering that it causes. This [event] is our commitment at the institute to beginning that journey and going down that path.”