Rider satisfaction with Muni has increased 12 percent in the past four years, according to the results of a telephone survey of 620 San Francisco residents who had traveled on the system in the past six months. The February survey showed that 64 percent of respondents rated Muni service as excellent or good, up from 52 percent in 2010, according to the San Francisco-based marketing and research firm Corey, Canapary & Galanis. The 64 percent figure – “a good rating,” according to firm owner Jon Canapary – breaks down to 14 percent “excellent,” 50 percent “good,” 30 percent “fair” and 7 percent “poor.” The 7 percent is “not surprising,” Canapary added. “It’s tough to move those poor ratings up, but the numbers in the middle are the ones you can really move to get an even higher rating,” Canapary told the San Francisco Municipal Transportation Agency board of directors at its meeting Tuesday. Rider satisfaction surveys have been conducted almost every year since 2001, with the lowest “excellent” and “good” rates the first year at 48 percent. However, prior to 2005 a five-point scale with the existing four ratings along with “very poor” was used. There was a “strong feeling” that the initial scale had three negative rating options whereas the current scale has two positive and two negative options, Canapary said. The firm also found that ratings from customers who rode Muni less frequently were slightly higher. Among those who used Muni five or more days a week, 60 percent rated the service excellent or good, compared to 67 percent for those who used it several times a week and 65 percent for people who rode once a week or less. The lowest ratings of Muni’s attributes were its communication with riders and vehicle cleanliness at 49 percent each, along with managing crowding at 31 percent. Cheryl Brinkman, vice chair of the SFMTA board, said she was “really pleased” to see the results. “These questions are addressed to people who actually use the system, and I think we’ve also gotten used to criticism of our system from people who don’t actually use it,” she said. The survey results have a plus or minus of 3.9 percent. Respondents were all adult residents and interviews were conducted in English, Spanish and Chinese. The public also can weigh in online for a survey about Muni’s new light-rail vehicle fleet.