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Sloat & Skyline Intersection Alternatives Analysis

Project Introduction
PROJECT SUMMARY & STATUS: 

SFMTA staff worked with a consultant team to evaluate two high-level design concepts to improve traffic flow and safety at the Sloat Blvd & Skyline Blvd intersection — one considering adding a traffic signal and the other a roundabout. Since two of the three approaches to the junction are under Caltrans jurisdiction, staff engaged state traffic engineers to evaluate the specific trade-offs of the two concepts.

Appreciating the high cost of a complete intersection re-build – whether for a traffic signal or roundabout – and the vital need for improvements, SFMTA staff are advancing a near-term traffic signal upgrade that retains the existing geometry of the intersection. Traffic signals will be added for all three approaches to the intersection, and curb ramps will be upgraded to meet current accessibility standards. This work is expected to be complete by early 2024.

SFMTA staff are also developing the Sloat Blvd Quick-Build Project, which aims to improve safety and enhance active-travel options on Sloat Boulevard between Skyline Boulevard and the Great Highway, connecting Lake Merced, the San Francisco Zoo, and Ocean Beach. The project will upgrade pedestrian crossings, add a two-way protected bikeway, improve accessibility, and consider other measures to reduce vehicle speeds while keeping traffic moving.

The Sloat & Skyline Intersection Alternatives Analysis was a planning-level project to evaluate design options to improve traffic safety and operations where Sloat Boulevard, Skyline Boulevard (CA-35), and 39th Avenue intersect.

The primary goals of the project were to:

  • Improve safety for all road users
  • Increase the visibility of people walking and bicycling and reduce intersection conflict points
  • Improve or maintain transit and vehicle circulation at the intersection

This project sought to identify options to make the intersection a more inviting, safe, and comfortable experience for all users.

This project is made possible by the San Francisco County Transportation Authority through a grant of Proposition K Local Transportation Sales Tax Funds.


SAFETY

Safety at the intersection of Sloat Blvd, Skyline Blvd, and 39th Ave in the Outer Sunset is unsatisfactory. Between 2008-2012:

  • 6 people were injured in traffic collisions at the Sloat & Skyline intersection
  • 46 people were injured in traffic collisions within a quarter-mile of the intersection
  • 2 deaths were reported within a quarter-mile of the intersection since 2014

EXISTING CONDITIONS

Existing intersection conditions include:

  • 2 pedestrian crossings
  • 4 Muni stops for the 18, 57, and 23 lines
  • Bike lanes to the west of the intersection and sharrows to the east
  • A four-way stop, accompanied by two 'slip' right-turn lanes
  • A speed limit of 35 mph, 5-10 mph greater than other high-use corridors throughout the city

OUTREACH – WHAT WE HEARD

In the summer and fall of 2017, SFMTA and San Francisco Public Works partnered to hold five outreach events to gather community members' concerns and perceptions about existing conditions at the intersection of Sloat and Skyline. These outreach events included an event at Java Beach Cafe, a walking audit of the intersection with community members, pop-up events during the week and weekends, and a stakeholder discussion. The feedback and observations from those events informed the technical study evaluating the intersection. After our robust public outreach process, staff identified three main areas of concern:

  • Pedestrian safety crossing the intersection
  • Bicycle safety moving through the intersection
  • Vehicle speeds approaching and moving through the intersection

Additional summary of comments heard include:

  • Crossing the intersection by foot is indirect
  • People driving do not always respect traffic laws
  • People walking actively avoid using the intersection
  • People bicycling find the intersection confusing with no clear path of travel
  • People driving often approach the intersection too quickly
  • Posted speed limits seem higher than what should be allowed
Project Timeline 
2017
Preliminary outreach
Completed
2018-2020
Develop design concepts
Completed
2020-2021
Evaluate design concepts (to inform future project)
Completed
Project Status
Completed
Improvements
walking
Improved safety and comfort of crossing the intersection on foot
bike
Improved safety and comfort of crossing the intersection by bike
SFMTA Drive and Parking icon
Improved traffic flow and intersection navigability
Bus Routes and Rail Lines
Neighborhoods
Streets
Sloat Blvd., Skyline Blvd., 39th Ave.
Caltrans Logo
San Francisco County Transportation Authority logo