New study:
In addition, they incur costs of 9.3 trillion U.S. dollars annually—8.3 percent of global economic output. Drivers pay 2 trillion, while 7 trillion represent so-called social costs borne by society—such as those resulting from accidents, air pollution, noise, climate damage, land use, and road infrastructure.
https://www.sciencedirect.com/science/article/pii/S0965856426003769?via%3Dihub