YANGON, Myanmar — To ride Yangon’s charmingly decrepit Circle Line train is to ride through history. Built more than 60 years ago to connect rural suburbs and townships to the city’s commercial heart, its trains — some almost as old as the line itself — move nearly 100,000 people a day, in a slow, 28-mile loop around Myanmar’s biggest city.

Like much else in the country, which is still emerging from decades of isolation under military rule, the Circle Line is a functioning, if fading, piece of the past. But modernization is on the way, and commuters who take the train daily say it cannot come soon enough.