Week of Jan. 31, 2006

Metro’s hybrid buses delivering on their commitment to cleaner air

A year after rolling out the final of 214 new hybrid buses, King County Metro Transit reports the nation’s largest fleet of articulated hybrid buses is logging better fuel economy than their conventional diesel cousins.

A year’s worth of performance data also show the buses are delivering on their promise of lowering greenhouse emissions and providing rock-solid reliability.

In an effort to independently document performance, Metro teamed up with the National Renewable Energy Lab, a U.S. Department of Energy-funded environmental testing lab in Denver, Colo. to help build a nationwide database detailing hybrid transit vehicle emissions. As part of the data collection program, a Metro hybrid bus and a conventional bus were taken to Denver for controlled laboratory testing. While a formal report is not expected until mid-2006, preliminary data confirms Metro’s findings.

and an estimated eight million miles later, the hybrid buses are demonstrating a 32 percent reduction in greenhouse gas emissions compared to the conventional diesel fleet. The hybrids are also proving to be 41 percent more reliable than their articulated diesel counterparts, which means they have less down time and require fewer parts and repairs. Passengers seem to like them, too. Metro says the most common feedback shows general satisfaction with their smoother and quieter ride.

The hybrid buses are also getting good mileage. Over the past year, Metro says the hybrid fleet’s overall fuel economy rated 31 percent higher than its newest fleet of 30 conventional 60-foot diesel buses.

“The data we have collected based on 660,000 city miles logged each month by the hybrids confirms these buses have become top performers in our fleet,” Metro Maintenance Manager Jim Boon said. “Not only will they ensure clean and efficient operations in the Downtown Seattle Transit Tunnel when it reopens, these hybrids are proving to be so good, they may play an even larger role in the Metro fleet in future years.”

As solid as the new hybrid buses are, the “human element” has also been a major factor in the overall quality of the hybrid fleet.

The adaptability Metro maintenance workers to learn a new operating system kept things humming under the hood. On the road, it was the more than 2,000 bus drivers who were specially trained to drive the 60-foot coaches who made the first year such a success.

In addition to operating 214 hybrid buses and another 22 hybrids for Sound Transit Regional Express, Metro runs 155 electric trolleys and uses Ultra Low Sulfur Diesel Fuel to power its entire fleet. The agency also uses a five-percent blend of biodiesel fuel to run a portion of its fleet, making it one of the most environmentally conscious transit operators in the nation.

The new hybrid buses were developed by consortium of nationwide companies that included Allison Transmission, a division of General Motors; New Flyer of America and Caterpillar. The hybrid buses make up approximately 16 percent of the agency’s fleet, cost $645,000 each and are projected to have a minimum life span of 12 years. Each bus will travel 35,000 – 40,000 miles annually.

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