Trains and heavy trucks both run on diesel, and a single locomotive can pull the load of about 280 trucks with about 30 times the emissions of one truck. But increased vehicle congestion at railroad crossings and the fact that trains usually spend a lot of time idling could turn out to reduce the possible air pollution benefits of increased use of rail freight. No doubt both trucks and trains will be needed in greater numbers with the goods movement industry expecting to triple the amount of cargo coming into California ports by 2025.
Any use of newer, cleaner technologies in locomotives such as electric, natural gas and hybrid diesel is likely to take a long time to become integrated into rolling stock across the U.S. with only about one new locomotive being built a week.
Analysis: BNSF has 6,300 locomotives. If they were to replace one locomotive per week with a new, cleaner model using say diesel-electric hybrid technology coupled with particulate filters and the like, it would take BNSF 121 years to completely retire their current locomotives. This is a problem.