Nothing says "drive yourself" like the sight of a bus catching fire on one of downtown Boise's busiest streets. We imagine that ridership on city buses, already not exactly overwhelming, went down a wee bit when, late in March, a bus burst into flames while it was idling in front of the Grove Plaza. Nobody was on the bus, nobody was hurt, but did anybody notice an uptick in commuters the next week? More bikes on the road, perhaps? Hey, Boise, we know you're trying to do the right thing, but let's face it, when you've got a bus that redefines the phrase "clean burning," right there in front of commuter central, it's hard to sell the hoi polloi on getting on board. Especially when they're just not sure whether their city bus will spew low-fume emissions, or a mushroom cloud.