As reported on San Francisco Streetsblog:
On five Muni lines, the time buses spent at stops dropped by as much as 16 percent in July compared to June, according to a presentation [PDF] prepared for the SFMTA Board’s Policy and Governance Committeemeeting this week. The most drastic change in “dwell times” were reported on the 1-California line and its rush-hour express companion, the 1AX, which saw decreases of 14 and 16 percent, respectively. The 1AX also saw by far the largest shift in passengers using the back door instead of the front door, with a 1,200 percent increase
The article goes on to note improved conditions on other lines reviewed:
The 49-Van Ness, the14-Mission, and the 38-Geary — saw more modest drops in dwell time. The 49, at the low end of the spectrum, only saw a decrease of roughly 1 percent. One possible explanation is that back-door boarding was already common on those lines before the policy change, compared to the 1-California.
All in all, the change seems to be a welcomed innovation. For a reminder of how all-door boarding differs from conventional front-only boarding take a look at this informative – and comical – look at the system made by the SFMTA.