John Muir Drive, which runs along the south side of Lake Merced, was upgraded last month with bike lanes separated by posts and buffer zones on some stretches. The SF Municipal Transportation Agency also converted angled parking spots on the road to the safer back-in angled configuration, which lets drivers see their path better when they pull out.

The one-mile John Muir Drive connects Skyline Boulevard to Lake Merced Boulevard, which has bike lanes that lead to Daly City. A shared bike and pedestrian path circling Lake Merced already exists, but the new bike lanes provide a new on-street option for bicycle riders who prefer it.

The project is one of the later projects to be rolled out from the SF Bike Plan, which is now over 75 percent complete, according to the SFMTA. The post-separated, buffered sections of bike lane and back-in angled parking don’t appear in the original plan [PDF], and it appears planners revised the project to add those features.

Back-in angled parking was included in the agency’s “Innovative Bicycle Treatment Toolbox” as a safer way to design bike lanes alongside car parking. SFMTA staff said a curbside, parking-protected bike lane would require more funding and planning to implement, since it would require measures like new curb ramps and raised buffers to prevent drivers from backing into the bike lane.

The speed limit on John Muir is 30 MPH on the western portion, near Skyline Boulevard, and 40 MPH on the eastern portion, according to an SFMTA report [PDF]. SFMTA staff said the buffer treatments were only used on the southbound bike lane on the road’s southern stretch, so not all of the high-speed stretches of the road will have this level of protection.