Part of Great Highway will be permanently closed to cars
A mile-long portion of protect the city’s western shore from rising sea levels.
City officials have long conceded that chronic and worsening coastal erosion would force the ultimate closure of what’s known as the Great Highway Extension between Sloat and Skyline boulevards. The roadway has been pegged for closure by the city since 2012.
The city has used stopgaps, such as a giant sand berm, in recent years to stabilize its rapidly deteriorating shoreline. But the highway, along with underground infrastructure and a major wastewater treatment plant are at risk of being overtaken by the rising sea.
The highway segment connects motorists from Skyline Boulevard to the rest of the Great Highway that runs through the Sunset District. The extension’s permanent closure means that drivers heading southbound on the Great Highway toward the Peninsula will have to turn on Sloat Boulevard to reach Skyline Boulevard.
It’s a detour westside drivers are already familiar with, as sand accumulation on the Great Highway Extension has often forced temporary closures and reroutes.
The city’s Public Utilities Commission and Recreation and Park departments plan to build a milelong trail and beachfront plaza in place of the closed roadway.
Renderings presented by the agencies to city supervisors this week show a new “Sloat Plaza” offering access to Ocean Beach that would begin at the northern crosswalk of the Great Highway and Sloat Boulevard.
The beachfront open plaza will occupy the current roundabout at the Sloat intersection with bollards protecting it from car traffic, according to renderings. The plaza will feature a new restroom building and connect to a multi-use trail that will be converted from two of the highway extension’s car lanes.
The city’s “Ocean Beach Climate Change Adaptation Project” calls for building a staircase to the beach shore on the southern end of the Great Highway Extension. That part of the closed roadway will also feature a one-way parking lot and drop-off area that drivers can access from Skyline Boulevard.
Emergency vehicles will be able to access a one-way service road on the Great Highway extension. The road’s closure means zoo visitors will lose access to the zoo’s parking lot from the Great Highway, though Supervisor Myrna Melgar said during Monday’s Land Use and Transportation Committee meeting that the zoo plans to build a new parking entrance near 47th Avenue.
The full Board of Supervisors will vote on the Great Highway Extension’s permanent closure to cars later this year.
The new plaza and trail on the Great Highway Extension could eventually become part of a fully pedestrianized waterfront park that connects to the existing Great Highway between Sloat and Lincoln Way.
City supervisors voted in December 2022 to reopen this segment of the Great Highway to vehicles during the week, while closing to car traffic on the weekends. The Great Highway’s hybrid configuration runs through the end of 2025 — at which point supervisors will have made the contentious decision over the highway’s longterm fate.