Those plans include the permanent conversion of that 150-foot length of Mason Street into public open space in order to connect the new library to the playground next door.Some neighbors protested that a long-term closure of this portion of Mason Street would cause traffic disruptions in the entire neighborhood. In response to those concerns, the Library, Recreation and Park Department, and Department of Public Works worked with neighbors to include a temporary closure of the block as part of the scope of the environmental impact report required of the proposal.
The SF Planning Department will collect data on traffic at a number of intersections near site. They'll compare that information to data from a period when Mason is open to cars in order to gain insight on the impact of the closure. Planners will also make qualitative observations of traffic, transit and bike/ped activity in the neighborhood during peak hours while the street is closed to cars.
Mason Street between Lombard and Columbus will be closed from August 1st to Septemper 27 - so very soon! With luck, activities will be booked for the new temporary plaza, and since the timing of the closure coincides with some of SF's best weather this might be the next Castro Plaza.
Enrique Peñalosa would be proud.