King County Metro in the United States is considering implementing a pilot project that involves the addition of up to four hydrogen fuel cell buses by 2026. These buses, known for their zero-emission operation and use of hydrogen as fuel, offer an extended range and emit only water vapor, making them environmentally friendly. This initiative is part of Metro's broader strategy to transition to a 100% zero-emission fleet in an effort to enhance sustainability and combat air pollution. By evaluating the performance of hydrogen fuel cell buses, Metro aims to assess their potential to complement existing battery-electric and trolley buses. The project is seen as a step towards benefiting riders, improving local air quality, and addressing the challenges posed by global climate change. King County Metro's forward-thinking approach underscores its commitment to innovation and environmentally responsible public transportation.