San Francisco transportation officials have released the most comprehensive analysis yet of traffic changes following the creation of Sunset Dunes Park, revealing that the controversial road closure has caused manageable but noticeable impacts on west side commuting patterns four months after the oceanfront park opened.
The Spring 2025 Outer Sunset Traffic Data Report, released Friday by the San Francisco Municipal Transportation Agency (SFMTA), found that traffic circulation changes were “largely aligned with transportation model predictions” following the permanent closure of the Upper Great Highway between Lincoln Way and Sloat Boulevard in March. The closure created California’s largest pedestrianization project, transforming the two-mile coastal stretch into a 50-acre park that officially opened as Sunset Dunes on April 12.
Traffic Impacts Align with Predictions
According to The San Francisco Standard, early data in April showed significant traffic increases on alternative routes, with the Lower Great Highway seeing more than doubled traffic during peak commute times. The latest SFMTA report confirms these initial findings while providing a more nuanced picture of the changes.
The agency found that Sunset Boulevard experienced a 28% increase in traffic but remains at only 90% of pre-pandemic levels. The San Francisco Examiner reported that Chain of Lakes Drive saw a 21% increase in traffic, within SFMTA’s predicted range of 20% to 25%. Lower Great Highway gained approximately 700 additional vehicles per weekday, representing about 5% of trips formerly made on the Upper Great Highway.
Muni Service Sees Mixed Results
Public transit impacts varied by route, with the 28 19th Avenue line experiencing the most significant delays. According to the SFMTA data, southbound 28 service saw an average increase of 104 seconds over its 4.6-mile route, rising to 110 seconds during evening peak hours. The 29 Sunset route had more modest impacts, with an average daily increase of 26 to 33 seconds, though evening southbound trips increased by 71 seconds while morning southbound trips actually improved by 44 seconds…