“When you look at other large systems — Paris, London, Toronto — you can really see and appreciate that these open-end car designs provide additional space,” Ms. Hakim said in an interview.

To make it easier for riders to enter the cars, the new trains will have 58-inch doorways, up from 50 inches, though Toronto’s doorways are 64 inches. (To be fair, Toronto’s system is far from perfect; it still accepts tiny tokens while New York retired the coins more than a decade ago.)

Toronto’s reputation as a livable city with good transit has helped it grow to more than 2.8 million people, on par with the population of Chicago. Toronto’s transit system — the third largest in North America — has about 1.7 million riders each weekday on its network of subways, streetcars and buses, but those figures are dwarfed by New York City’s nearly 6 million daily subway riders.

Toronto’s transit system is facing major crowding challenges and uncertainty over funding. The city has three main subway lines, and its busiest, the Yonge-University line, is regularly packed at rush hour, mirroring conditions on New York’s busiest lines.

Steve Munro, a longtime transit advocate in Toronto, said that the new cars had helped with crowding, but that the city should have built new subway lines to handle the rising demand decades ago.

“By the time you realize you need the new trains, you already have a crowding problem, and there is a backlog of demand that will immediately fill the new capacity,” Mr. Munro, 67, said at a cafe near the busy Bloor-Yonge station.