Until now, U.S. studies of how much pollution cars and buses produce have been limited to tailpipe emissions and the equivalent, for other ways of getting around. But, four years ago, UC Berkeley doctoral candidate Mikhail Chester recognized that there is more to our vehicles than a tailpipe.
"All of the components associated in the infrastructure, the vehicle itself, manufacturing the vehicle, maintaining the vehicle, producing fuels," he pointed out.
Chester's civil and environmental engineering PhD project looked at greenhouse gases and other pollution produced over the lifetime in what is called the "lifecycle" of cars, trains, planes and buses. He also looked at the infrastructure needed to support them.
"Building roadways, maintaining roadways, building a train station, building an airport, operating an airport, we looked at salting roadways, spraying herbicides along railroad tracks," were among the activities he listed.
Chester found that for cars, when adding in the lifecycle components, the pollutants produced by that one vehicle, increased by 50 percent. For trains it is worse.
"It's almost a doubling. So, the electricity that's required for a train system to operate, if you double that electricity and the associated carbon dioxide emissions, there's the total lifecycle effect," Chester explained.
And, as polluting as a 747 might be, what it leaves behind is worse.
"One of the surprising results is that for aircraft, the majority of carbon monoxide emissions are not from aircrafts themselves, but from ground support equipment, particularly the gasoline baggage tractors," he pointed out.
Not so surprising, when comparing emissions per passenger, an empty bus is the worst while a full bus is the best. Chester's research shows there really is no such thing as "zero emissions" buses because the manufacturing of the bus, its tires, building the roads for it and so on, all create emissions.
Now that the research and the PhD are completed, Chester is getting some attention. He made June's Popular Science magazine and transportation agencies are taking notice.
Professor Arpad Horvath was his advisor on the project.
"The most important and probably the most exciting implications of this will not be just to tell the individual passenger what steps to take, but also influence societal scale planning," he said.
San Francisco MTA Assistant Deputy Director of Transportation Planning Tim Papandreou says the study is a useful tool.
"Because of this report we can plug some of the data holes that we had, and now it can help us inform and make better decisions when we do our bicycle planning and our transit effectiveness project, and any other corridor projects that we do like our central subway for example," he said.
Chester and Horvath are not done. They want to finish an analysis of California's coming high-speed rail system and they are working on a comparison of emissions in San Francisco, Chicago and New York.