I am heard on NPR: To Get Around Town, Some Cities Take A Step Back In Time talking about Streetcars:

“City officials say for every public dollar spent, they will get two to three times as much private investment. But David Levinson, who teaches transportation engineering and economics at the University of Minnesota, says there’s no guarantee. He says cities are better served upgrading their bus service.

‘There’s a lot of money you’re just putting into the ground. It doesn’t provide any transportation benefit. It’s basically a lot of embedded capital that is costly that doesn’t make the system work any faster,’ he says.”