The San Bernardino County Transportation Authority in California is progressing towards launching North America's first hydrogen-powered passenger train for regular usage. The zero-emission multiple unit trainset, known as ZEMU, is entering its second phase of testing on the 9-mile Arrow route in San Bernardino, California. The train utilizes a blend of hydrogen fuel cells and batteries to drive its propulsion system, emitting solely water vapor as a byproduct. Scheduled to operate on weekday nights between 9 p.m. and 4 a.m., the train will undergo extensive testing to evaluate its operational performance. The agency's long-term vision towards developing zero-emission rail transit technology has materialized through a partnership with Swiss train manufacturer Stadler. The ZEMU train arrived in the U.S. after rigorous testing in Europe and Colorado, with the aim of commencing service in early 2025. This milestone project underscores the region's commitment to sustainable transportation and marks a significant advancement in eco-friendly public transit solutions.