Four Steps to Cleaner Buses

School buses are still the safest and smartest way to travel to school. But with lower diesel emissions, they could be even safer. New buses and retrofits are good solutions. Here are four ways to make a difference:

#1: Replace - Add new buses over time

New buses are much cleaner than older ones. Thanks to strict new Environmental Protection Agency standards, new 2007
buses are 90 percent cleaner than the buses they replace.

New buses are expensive, however. (A new bus costs $75,000-80,000.) One solution for cash-strapped schools is to outfit buses older than 1995 with newer engines and retrofits.

#2: Retrofit - Filters clean up older buses

Affordable pollution-cutting filters are available. For just $9,000-15,000 each, older buses can be fitted with tailpipe and crankcase filters that reduce soot emissions by up to 90 percent, making them as clean as new buses for a fraction of the cost.

Every dollar spent on retrofitting a diesel school bus is worth at least $12 in health benefits (such as avoided emergency room visits) — a very smart investment.

State-of the-art technology and ultra-low sulfur diesel, now required for diesel trucks and buses, will result in cleaner-burning buses. (Read story "End of the Road for High Sulfur Diesel".)

#3: Reduce idling - Turn off engines

Eliminate idling. Bus engines should be turned off when waiting, especially within 500 feet of a school. During hot summer or cold winter months, drivers can make arrangements to wait inside schools between jobs, or auxiliary power can be used to warm or cool the bus.

When a bus remains running for more than three minutes, emissions from the bus increase more than 65 percent. Buses also waste countless gallons of gas through idling. By reducing idling a 25-strong bus fleet can save thousands of dollars a year in fuel costs.

Other ways to minmize the effects of idling:

• Line up buses diagonally rather than single file. When buses park in single file, the exhaust flows easily filters into other buses through open doors.
• Move the exhaust pipe to the opposite side of the bus to minimize pollution from entering the doors of adjacent waiting buses.

Solution #4: Routing - Encourage smart fleet use

• Routes and travel times should be scheduled to achieve the most efficiency. Bus companies and school districts will save money, too. 
• The cleanest buses should travel the longest distances and the most days.

Posted: 01-Jan-1900; Updated: 28-Apr-2008