An electric plug icon on their windows makes them easy to spot in cities like Brussels and Madrid. Quietly navigating the streets, electric buses have become an increasingly common sight on Europe's streets in recent years.

Michela Le Pira, assistant professor of transportation at Italy's University of Catania, says removing tailpipe emissions — the gases and particles generated when a combustion vehicle is running — might be "the easiest strategy to improve public transport."

Most Europeans live in urban settings, and road transport harms air quality. In 2023, almost 300,000 deaths across the EU were caused by air pollution levels exceeding the World Health Organization's (WHO) recommended thresholds.

Of all fine particulate matter (PM2.5) concentrations in European urban areas, about 14% come from road transport, including public, private and freight transport.…