Busses are a lot more flexible in terms of routing - normal gasoline busses can be rerouted at will, and the cost of changing routes for electric busses (like t

Busses are a lot more flexible in terms of routing - normal gasoline busses can be rerouted at will, and the cost of changing routes for electric busses (like the ones in Seattle) are much lower than street cars, where you basically have to lay new track. That's actually a downside of buses when it comes to urban development. As a business owner, there's very little upside in opening up a new business next to a new bus stop, because I know that bus stop may move (or disappear entirely) next year. Compare that with a light rail line, which is guaranteed to be on a fairly fixed route, with fairly fixed stops. The literature I've read about urban development shows that additional bus lines do almost nothing for economic activity along their route, while light rail lines have significant, sustained increases in economic activity near their stations.