Buses and trains will be a crucial component of decarbonizing the transport sector. They currently release about one quarter of the emissions per passenger-kilometer (pkm) as compared to emissions generated by ride-hailing services and about half of those from a private vehicle.
Across the world’s 50 highest-emitting cities, the number of kilometers (km) of rapid transit per million people has increased over time, from 16 km in 2010 to 19 km in 2020. These include metro systems, light rail and bus rapid transit (BRT), which uses a dedicated lane to avoid the causes of delay that typically slow regular bus services. Europe outpaces the rest of the world in terms of its rapid transit-to-resident ratio, followed by Chile, Ecuador, South Korea and Tunisia.
To achieve a pathway compliant with the 1.5 degrees C (2.7 degrees F) target, rapid transit in cities would need to reach 38 km per million people by 2030. This would require the pace of change achieved over the last five years to increase by 6 times.