Muni's on-time performance rate continues to lag well behind its voter-backed mandate, although the transit agency has slightly improved its service recently.

For the second quarter of this fiscal year, which covers October through December, Muni vehicles arrived on-time for 71.7 percent of their runs, according to agency documents.

That marked a small spike from the previous fiscal quarter, when vehicles tallied a 71.1 rate, but its falls significantly short of an 85 percent benchmark established in 1999 when voters opted to expand the agency.

Muni spokesman Paul Rose said the second quarter’s numbers "are what they are," but he added that the agency is committed to improving system reliability and the customer experience.

wreisman@sfexaminer.com