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The WKD light interurban rail line in Poland used to have trackage on the streets of Warsaw and other towns adjacent to it until 1974 when it has been ruled that rail equipment heavier than trams cannot enter the city's streets and the line was rerouted next to a long-distance mainline, with terminus located right in the center of Warsaw for more convienient changes to other trains and urban public transport. WKD indeed resembles a tram in many ways (ie. the 600V DC power supply or narrower clearance) but the way of operation is strictly railway-like, which was the reason why it was withdrawn from the streets onto separate right-of-way.
Pic related: two class EN94 units on the Szczęśliwicka street in Warsaw, around 1970. These units were in service until 2015 when voltage has been switched to country-wide 3000V DC standard.