In the face of the mid-century GM streetcar conspiracy in North America, there were very few options for off-the-shelf streetcars. Toronto ended up working with a provincial agency (UTDC) to develop a design that would meet contemporary needs. It was really a world-class effort: the prototypes were built in Switzerland, adjusted for Toronto track gauge and marketed to Boston (who ended up going with a Boeing design).

In a very oversimplified explanation, most major rail manufacturers now offer something that’s like a kit: cities pick length, types of operation (street running or separate grade), front-end and back-end design and that’s it.