This piece from the San Francisco Chronicle argues that the best way to improve the city's sluggish public transit system is to put it underground.
"Throughout the world, cities have recognized that dense urban areas can be adequately served only by separate rail rapid transit. We have the BART and Muni Metro systems, which provide this level of service to some parts of the city, but the densest quarter, north of Market Street and east of Van Ness Avenue, has no subways. We passengers have to endure buses that crawl along at walking speed. The planned Central Subway, which is an extension of the new T-Muni-Metro line, is our chance to finally provide world-class service to this part of the city."
"The Central Subway corridor is the fourth of four new rapid-transit corridors approved by voters in 1987 as part of the "four corridors plan." One, the Third Street lightrail line, has been built. Another two, Geary Boulevard and Van Ness Avenue (both of which are wide streets that can accommodate exclusive transit lanes), are slated to get Bus Rapid Transit. The Central Subway is the final link in this modern rapid transit system that is long overdue. A trip from Fourth and King streets to Chinatown that takes 22 minutes on a good day, longer if traffic is bad, will take seven minutes, every time, on a comfortable train."
"The San Francisco Planning and Urban Research Association supports this project, but with a couple of stern warnings. As proposed, the subway fails to make Muni much more efficient. Because it goes only as far as Chinatown, it does not directly serve much of northeast part of the city, therefore requiring slow, inefficient duplicative bus service to be retained. The subway should be extended to North Beach, serving a large population and allowing easy transfers from other lines. This could be done quickly and relatively inexpensively because the plan already calls for tunneling all the way to Washington Square, where an additional station easily could be built. Subsequently, the line could be extended to Fisherman's Wharf and the Van Ness rapid transit line, and from there possibly to the Presidio."