Transit bus fleets embrace clean diesel technologies

Houston, Texas – Advancements in new clean diesel technology that has resulted in a transit buses with near zero emissions is being adopted by U.S. transit officials at a faster pace than other large vehicle sectors, according to Ezra Finkin, director of policy for the Diesel Technology Forum.

Finkin made his comments this week at the American Public Transportation Association's (APTA) Expo Bus and Maintenance Technical Session in Houston.

Finkin explained that U.S. transit agencies were adopting clean diesel technology at a faster percentage than the heavy duty trucking fleet. Nationally, 44% of the diesel transit buses meet or exceed the first EPA clean diesel standard – Model Year 2007 or newer – while 33% of the U.S. truck fleet meet or exceed the standard.

"The rate of adoption by transit agencies of clean diesel technology surprised us and is very significant, since transit agencies are at the forefront for evaluating the best fuels and technologies to serve their communities," Finkin said. "It also comes at a time when there are a growing number of technology choices, incentives and pressures on transit fleets to procure technology to meet local clean air, energy and climate objectives.

"The new clean diesel bus technology of today is the result of an interconnected system of clean fuels, advanced engine design and exhaust or aftertreatment technologies working together to reduce emissions to near-zero emissions. New clean diesel buses have reduced both NOx and particulate matter emissions by 98% compared to 1988 buses.

"Fuel savings as well as hybrid and biofuel capabilities will also allow diesel to be a part of a sustainable transportation future. The result is that we expect clean diesel to be the technology of choice for the U.S. public transportation fleet for decades and decades to come," Finkin said.

Finkin noted that APTA's 2013 data showed the share of fuels and engines in the public transit bus fleet in 2013 consisted of:

• 77.71% diesel
• 19.90% compressed natural gas
• 0.96% liquefied natural gas
• 0.20% hydrogen
• 0.11% electric
• 0.10% gasoline and electric
• 0.08% propane

Of the diesel buses currently in the U.S. fleet, Finkin said APTA's data showed that 81% were conventional diesels, 12% were diesel-electric, and 7% operated on biodiesel.

Source: Diesel Technology Forum