I guess since we're posting interurban systems, too, here is an old map of Detroit's interurban lines circa 1913:
And another typology from 1915:
This entire system is gone. Detroit United Railway (DUR) was the private owner and developer of most of the original streetcar lines and many of the interurban lines, which they'd all bought up until the 20's. It was at this time when Detroit was trying to create a more comprehensive system that the city's Department of Street Railways (DSR) bought many of the lines as the DUR unraveled itself. By 1928, DUR had pared itself down to a single interurban line between Detroit and Toledo and had re-organized itself as Eastern Michigan Railways before going out of business in the early 30's.