Clean Bus, Clean Air

A sleek new bus rounds the corner and stops at UVM's Royall Tyler Theater. Every 21 minutes, this Redstone Route shuttle arrives here to pick up students on its loop around campus. But unlike buses in most cities around the world, this is not a noisy vehicle spewing a black cloud of diesel smoke.

It sounds quiet and there is no smell from the tailpipe. Its secret? The bus runs on compressed natural gas, one of two CNG vehicles on campus put into regular service this spring.

The natural gas fleet will grow to six vehicles by fall 2008. the product of a partnership between UVM, the City of Burlington, Vermont Gas Systems Inc., and the Federal Transit Administration to improve air quality and develop Vermont's first "fast-fill natural gas refueling station. Sen. Patrick Leahy provided key leadership on the project, securing a $2.4 million appropriation through the federal Clean Cities Program.

It’s an investment in public health. Motor vehicles are the largest source of toxic and cancer-causing air pollutants in Vermont. "Particulate pollution on these CNG buses should be about 100 times lower than what you get from typical buses, says UVM engineering professor Britt Holmen, an expert on vehicle emissions.

And, compared to petroleum diesel, compressed natural gas emits about 50 percent fewer nitrogen oxides, a major contributor to smog, greenhouse gas formation and, like particulate pollution, a cause of respiratory health problems. As an added benefit, natural gas engines reduce noise pollution; they are about 15 decibels lower than diesel.