There has been a lot of talk of streetcar networks lately. Just to share a few of the cities that are discussing not just one line, but a network.
Portland: Obviously their first line has been a success and now they are looking to expand. Citizen planning has already begun and a review of corridors will be underway shortly. They also have a leg up given the United Streetcar folks would make cars for them in town.
Seattle: Construction on the South Lake Union streetcar line is almost complete and there are plans for a more extensive network. There are maps in this report.
Minneapolis: After the success of the Hiawatha Line, Minneapolis is ready for expansion. They are in the third stage of planning for a streetcar network downtown that would consist of a number of corridors.
Washington DC: Plans for a streetcar network are beginning with the Anacostia Streetcar however they have hit a snag with some overhead wire rules that have been discussed earlier in the blog. But that hasn't stopped them from planning corridors or having the first streetcars tested.
Some cities such as Baltimore are hopeful, but haven't gotten into the planning stages yet.
I think its important to think big. As i've said before, one line does not a transit system make, and its important to have a network so people can go more places. Streetcars serve a certain short hop circulation service in street and can be used for shorter line haul operations but there are some jobs that light rail, commuter rail, heavy rail, or bus can do better. But there's nothing like a good land use plan and a streetcar to rebuild a neighborhood.
(Sorry for the picture quality, but I took screen shots from the linked PDFs)