The poor on-time performance of San Francisco’s public transit, which the city started reporting accurately over the summer, is officially a trend.
Muni vehicles were on time 58 percent in September, up a little more than one percent from the previous month. But it was more than 10 percentage points lower than the numbers the agency regularly reported last year using what it said was flawed methodology.
A shortage of drivers and an aging fleet of buses contributed to last month’s poor performance, said Muni spokesman Paul Rose. Rose gave the same reasons for August’s report card.
The new figures, released Wednesday , fall far short of the voter-mandated goal of 85 percent. Muni has never met the goal, set in 1999 through the passage of Proposition E.
The last inflated figure, published at the end of last year, was 71 percent. Using a more accurate count, it was adjusted to 61 percent.
Muni did put out more service in September (96 percent of scheduled transit trips) compared with August (94 percent), which led to the slight on-time performance improvement, Rose said.
The transit agency is making some headway in dealing with its old buses and operator shortage. The Public Press reported last month  that Muni is purchasing 45 low-floor hybrid-diesel buses and upgrading 80 biodiesel buses. Those new buses though won'’ be arriving until next year.
Rose said the transit agency is putting in more resources in training operators to get them out on the streets as soon as possible. The agency reports that 19 new part-time drivers began work last month with an additional 24 drivers in training.
Muni has also focused on reducing the number of transit trips that encounter bunching of vehicles and gaps in service on the most heavily used bus and train routes.
The Bay Citizen reported in July that the transportation agency had been inflating on-time performance numbers for more than decade , which led to recent changes in on-time performance calculations For the last 10 years, Muni has been figuring on-time performance by allowing for a five-minute fudge factor. Now it only allows four minutes before a vehicle is judged to be late.