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.

Had no idea such a thing had ever happened. Interesting article.

General Motors streetcar conspiracy

https://en.wikipedia.org/wiki/General_Motors_streetcar_consp...

At least with rail vehicles (trams, metros and trains), I think custom designs used to be more common in the past. Perhaps the consolidation of all sorts of independent rolling stock manufacturers into Alstom has played a part in making it less common these days.