The MBTA found that CNG buses had the lowest lifecycle cost and cost per greenhouse gas reduction. Diesel-electric hybrids have maintenance issues, and battery

The MBTA found that CNG buses had the lowest lifecycle cost and cost per greenhouse gas reduction. Diesel-electric hybrids have maintenance issues, and battery electric and hydrogen buses have significant capital costs which makes it difficult to realize the significantly lower operational costs. https://www.abettercity.org/docs/Alternative%20Propulsion%20Systems%20Final.pdf https://www.abettercity.org/docs/Alternative%20Propulsion%20... However, even pure diesel buses are much more efficient at moving people than single-occupancy vehicles. It's also worthwhile to note that a real plan for reducing greenhouse gas emissions would necessarily include substantial capital outlays: not just bus charging infrastructure but grade-separated rail, dedicated busways, bus rapid transit, cycle and scooter infrastructure, etc. etc. Not to mention all the other climate adaptions that need to happen at an infrastructure level.