The San Francisco Muni is turning 100 this year. And in that century of great technological progress, in which an aircraft broke the sound barrier in 1947 and a supersonic car did the same in 1997, Muni has actually become slower.

In 1920, the F-Stockton streetcar carried passengers from the Financial District at Market and Stockton Streets all the way to the Marina at Chestnut and Scott Streets in a zippy 17 minutes. Today a very similar trip on the 30-Stockton, the successor to the F-Stockton, takes a half-hour if the stars are properly aligned.

“Streetcars ruled the road, and there wasn’t much getting in the way — no car traffic — and we didn’t have all the traffic lights and stop signs,” said Peter Straus, a retired Muni service planner. “Back then it was basically ‘load and go,’ ” he added, “and there was nothing to slow them down.”

San Franciscans were not shocked to learn that Muni ran faster 100 years ago.

“I wouldn’t be surprised if a horse-drawn carriage got there faster than Muni,” Angie Murphy, a regular Muni commuter, said recently as she waited for a bus in the rain in the Financial District.