Our teams have added new traffic signals to help support your trips in the Outer Sunset.
In March 2025, the city closed the Upper Great Highway and the Great Highway Extension, southbound, to make way for its newest park, Sunset Dunes. We have partnered closely with SF Rec and Park, Caltrans, Public Works and the San Francisco Public Utilities Commission to ease the transition for neighbors and commuters.
Once voters passed Proposition K, we got to work right away preparing for potential travel impacts. We used data from an extensive modeling effort – the San Francisco County Transportation Authority’s 2022 Great Highway Concepts Evaluation Report – to understand how travel patterns may shift, and to plan for street upgrades in advance.
Since the closure, we have been monitoring traffic closely and collecting data to understand travel impacts and make changes to improve conditions for people who rely on local roads to get around.
As part of this work, we analyzed vehicle volumes before and after the March 2025 closures, using traffic data from key streets across the Outer Sunset. What we found is that minor traffic shifts were largely aligned with traffic projections outlined in the SFCTA report. Learn what our latest data shows and what we’re doing next to support your trips through Outer Sunset.
Understanding traffic patterns: What the data shows
Some roadways are busier and more congested. Chain of Lakes Drive has about 2,000 more vehicles per day than pre-closure. Lower Great Highway has about 700 more vehicles per day – that means about one additional vehicle per minute at peak hour –compared with pre-pandemic traffic.
At the same time, traffic on the Upper Great Highway between Fulton and Lincoln has dropped by 30%. Together, these two major park crossings – Chain of Lakes Drive and the Upper Great Highway – now carry about 3,200 fewer weekday car trips than before the closure. This suggests that while some traffic has shifted to nearby streets, other trips may have moved to different routes, different types of transportation, or aren’t happening anymore.
Other roadways remain below pre-pandemic traffic. Sunset Boulevard remains at 90% of pre-pandemic traffic volumes. Lincoln Way east of Chain of Lake was not impacted by the closure of the Upper Great Highway and remains 7% below pre-pandemic traffic volumes.
While some traffic has shifted to avenues, all the avenues where we collected data had typical traffic volumes for neighborhood streets.
For more on the data we gathered, you can view our Spring 2025 Outer Sunset Traffic Data Report.
We are also closely monitoring travel times for Muni routes near the Upper Great Highway, including the 29 Sunset.
Muni has had minor and manageable changes in travel times
Our Muni buses travel routes next to the Upper Great Highway, and there were a range of travel time changes after the roadway closure.
- The 29 Sunset saw an average daily increase of 30 seconds in travel time. Conversely, the morning peak had a 44 second decrease in travel time in the southbound direction.
- The 28 19th Avenue experienced about 1–2 minutes of additional travel time in the southbound direction during peak hours (we are working on signal adjustments to reduce these travel times).
- The 18 46th Avenue, which runs directly next to the former Upper Great Highway, experienced no change in travel time.
What we’re doing to keep traffic flowing
Based on traffic data collected in May, we are proposing changes at key bottlenecks to reduce congestion and make it easier for everyone, especially our buses, to travel smoothly. These changes include new protected turn movements and turn restrictions at 41st Avenue and Lincoln Way, and signal timing adjustments on 19th Avenue.
We are also in the early planning stages for further long-term improvements to make sure Westside residents and visitors can travel smoothly. These upgrades include:
- New traffic signals at Lincoln Way & La Playa and Lincoln Way & 45th Avenue.
- Signal upgrades at Great Highway & Lincoln Way and Lincoln Way & 41st Avenue.
All of this builds on work we did well before the closure to prepare for potential impacts – and during the immediate transition period where we made changes to respond to community feedback and real-time conditions.
Learn about our proactive steps ahead of the closure to help reduce impacts.
Proactive improvements to support neighbors and visitors:
To prepare for the roadway closures, the SFMTA and our partners implemented targeted infrastructure upgrades to support traffic flow and safety, including:
- New signals at Sloat Boulevard and Skyline Boulevard, 41st Avenue and Lincoln Way and Great Highway and Skyline Boulevard.
- A full repaving and restriping of Sunset Boulevard between MLK Drive and Lake Merced Boulevard, completed in April 2025.
- Intersection improvements at Great Highway and Lincoln Way to support the full-time closure of Upper Great Highway. Upgrades included new signal timing, reconfigured lanes to improve traffic flow and a full-time separate bikeway connection to Golden Gate Park.
Responding to community needs in real time:
In addition to these infrastructure upgrades, we have made several changes since the road closed. We have made upgrades based on community feedback and conditions we are seeing on the ground. These changes include:
Additional signage to direct drivers to alternative routes
- Northbound Skyline to direct drivers to Sunset.
- Lincoln westbound reminding drivers that the Great Highway is open north of Lincoln – this is the suggested alternative to the busy Chain of Lakes route through the park.
- Sunset southbound to direct drivers to Skyline.
- Chain of Lakes southbound reminding drivers that MLK is also open to reach Sunset Boulevard southbound.
- 44th and Lincoln to remind drivers that Great Highway north of Lincoln is open to vehicles.
Additional signal adjustments to improve traffic flow
- Adjusted signal timings at 45th and Sloat to address congestion.
- Adjusted the operation of the new signal at Chain of Lakes and Lincoln Way/ 41st Avenue
What’s next
We understand that any time a street is closed, or changes are made that impact traffic flow, there will be an adjustment period. As our agency continues to monitor street traffic and patterns, we remain fully engaged with the community and our city partners.