With the Blake Transit Center located just outside Automobile Magazine’s front door, there’s no avoiding the Ann Arbor Transit Authority (AATA). Taking TheRide while attending the University of Michigan, I became intrigued by this system’s ambitious green initiative. Twenty of the AATA’s seventy-two buses are hybrids powered by a bio-diesel engine and two electric motors. The technology is a scaled-up version of GMs’ Two-Mode hybrid system that was chosen as our 2008 Technology of the Year.
When a Route 6 hybrid bus heading southeast toward AATA headquarters whirred to a stop at the Blake terminal, I flashed my student ID (in lieu of paying the $1 fare) to join a dozen other riders enjoying mass transit at its finest. The blue, gray, and white seating area was spotlessly clean. The air-conditioner’s cool breeze kept the bus’s interior free of diesel noise and odor. Regular riders smile when one of the hybrids appears at their stop, because these buses are smoother, quieter, and cleaner than their diesel-only counterparts.
Exiting four miles later, I met motor-coach operator Louis Sims at the AATA’s maintenance garage. He explained that every AATA bus has a Mobile Data Terminal (MDT) that uses GPS to track its progress so that riders can view updated departure information online. Sims invited me into the Recaro driver’s seat for a short run in the hybrid bus. Electric motors energized by nickel-metal-hydride batteries housed in a roof compartment propel this hybrid at speeds of less than 30 mph. The diesel engine runs continuously to power ancillaries and provide drive assistance above 30 mph. However, during my 40-foot test drive, I was most impressed by the hybrid bus’s braking power.
Mary Stasiak, the AATA’s community relations manager, revealed that a new 40-foot hybrid bus costs a staggering $546,000, which is $245,000 more than a comparable conventional bus. Grants from the Federal Transit Administration’s Congestion Mitigation and Air Quality Improvement Program ease the financial burden. Since the hybrids are 30 percent more efficient, half of their extra cost will be offset by fuel savings. Maintenance costs are expected to drop by 30 to 50 percent, because the hybrid’s regenerative braking doubles the life of the friction brakes and lowers the stress on suspension components. While it’s impossible to assign a dollar value to clean air, the hybrids also provide emission reductions ranging from up to 50 percent for CO2 and NOx to 90 percent for carbon monoxide, hydrocarbons, and particulate matter.
The Gillig Corporation of Hayward, California, manufactures 270 hybrid buses per year and guarantees them for the same twelve-year service life expected of a conventional bus. More than 1000 hybrid buses made by Gillig and five other manufacturers using the GM/Allison Two-Mode system are now operating in eighty-six North American cities and Yosemite National Park.
Even though the hybrids have been operating in Ann Arbor for less than a year, the AATA intends to switch its entire fleet to green machines as its conventional buses reach the end of their service lives. Two years ago, Ann Arbor’s city council established a greenhouse gas reduction target of 20 percent (lower than 2000 levels) by 2015. The AATA intends to do its part to meet that goal.