From a distance, nothing looked strange about the little yellow school bus parked at City Dock in Annapolis yesterday.
But up close, there were some clues - the three women in grease-stained T-shirts and jumpsuits, the giant frog ornament on the hood, and a sign - decorated with pictures of french fries - proclaiming that "this bus runs on veggie oil."
The "Indicator Species Traveling Roadshow" kicked off a two-month tour yesterday at the dock with a puppet show about the evils of garbage and pollution and a short demonstration of how they fill the fuel tank with vegetable oil.
It's a messy process that involves a vacuum pump to retrieve used cooking oil from restaurant disposal tanks, clean it with a clothlike sieve, and pump it into the tank.
As a backup, the bus also uses diesel fuel - as evidenced by the pungent odor inside the bus and the jumpsuit stains.
Contrary to the french-fries motif, the bus doesn't fuel up at fast-food joints.
Fat that clogs arteries apparently isn't good for engines either, said Gina Favano, the Philadelphia native who bought the bus and organized the trip.
"We mostly go to Asian restaurants - they have the best oil," Favano said. "The higher the quality of food a restaurant has, the higher quality the oil is."
For the record, she said, the bus, about half the size of a standard school bus, gets about 10 miles to the gallon of cooking oil and has a 35-gallon capacity.
Her crew yesterday consisted of Crofton native Jenny Lahn, a Pittsburgh environmental activist who goes by the name Etta Cetera, and Beth "The Pulse" Pulcinella, a graduate of Baltimore's Notre Dame Preparatory School who lives in Philadelphia.
Originally, the group wanted to come to Annapolis so the two local members could see their families. But when Dick Lahn, also an environmental activist, contacted city officials to arrange for the bus to stop at the dock, the trio learned that clean air has been a major focus for Annapolis Mayor Ellen O. Moyer's administration.
The Annapolis transportation department uses buses and a trolley that burn natural gas, and City Hall has two hybrid battery-and-gasoline cars that inspectors drive. The city has long known it has some of the worst air in the country, said spokeswoman Jan Hardesty, and is trying to clean up its act.
"We'd like people to know we've already started with our own clean-air policy," she said. "This bus is just one way of letting people know there are alternatives."
Favano got the idea for the bus while traveling in Australia, and spent the past year and a half learning - mostly from online sources - how to power it. She met the other two through a puppet show that was performing at the Republican National Convention in 2000.
They're going as far west as Austin, Texas, and as far south as Florida, sleeping on the bus or at the homes of supporters.