The ideal US-101 corridor through San Francisco, San Mateo, and Santa Clara counties serves the Bay Area equitably in service to three goals:

Goal 1
Goal 2
Goal 3
Project Goals

The US-101 MAP developed goals to focus actions around shared values of equitable access, reliability, prioritizing high-capacity mobility, and fostering safe and healthy communities. MAP anchors proposed actions on these goals by defining specific performance metrics that can be monitored and responded to over time. See the Evaluation tab for more detail.


Goal 1

Offer reliable travel times

Ensuring reliable travel times helps corridor users arrive on time to jobs, services, and other destinations. When a corridor is unreliable, travelers may have to add “buffer” time to their trip to avoid being late. This has the greatest impact on low-wage employees working hourly or shift jobs, which typically require stricter schedules and start times than higher-paid salary positions.

Reliability Performance Today

Today, travel on the US-101 corridor is not as reliable as it could be — travel delay is both expected and unpredictable. US-101 South has several regularly congested hotspots during peak commute hours, which make travel less reliable. In 2016 during the morning peak, US-101 from SR-85 to I-280/680 was the third least reliable highway segment in the Bay Area. SamTrans Route 398, which operates in mixed-traffic on US-101 rather than dedicated transit lanes, has an on-time performance of 63%. This is significantly less than SamTrans’ system-wide on-time performance for fixed-route buses.


Goal 2

Prioritize high-capacity mobility options, such as buses and carpools

Higher-capacity vehicles, such as buses or trains, move many more people than single-occupancy cars while using a similar amount of space. Prioritizing higher-capacity vehicles that are separated from congestion is a more efficient use of limited corridor space. Improving the occupancy of personal vehicles by encouraging carpools also helps move more people. Buses and other high-capacity options should be a viable option for everyone, regardless of income, age, ethnicity, and other socioeconomic factors.

High-Capacity Performance Today

US-101 is used primarily by single occupancy vehicles today. Only 13-22% of peak hour vehicles on US-101 have two or more passengers. Ridership and availability of public transit buses on the corridor varies widely. Using ridership figures from early 2020, SF Muni carries about 40,000 boardings per weekday on its four routes that use US-101 in San Francisco. SamTrans serves about 1,400 daily boardings on its two routes that use US-101 and VTA serves about 500 daily boardings on four routes. Caltrain and BART, which provide alternatives to driving on portions of US-101, carry a higher number of transit riders during peak travel periods. Although ridership data from employer shuttles is not always publically available, more than 200 shuttles use US-101 each day. As ride-hailing apps such as Uber and Lyft have increased in use, especially for airport trips, surface congestion in and around airports has increased and transit ridership has decreased.


Goal 3

Foster healthy and sustainable communities

Heavily traveled highways such as US-101 are significant sources of air pollution, including greenhouse gas emissions and particulate matter. Vehicles entering and exiting freeway access points can pose a danger to people walking and biking, particularly when there are limited and inadequate facilities to cross the highway.

Health and sustainability today

Traffic density is a measure of the number of vehicles on the roads in an area, and neighborhoods with more traffic density are also subject to more noise and air pollution from vehicles, and busier intersections. These impacts lead to higher asthma rates and other health effects and make it harder to walk and bike on neighborhood streets. The neighborhoods adjacent to US-101 interchanges and directly east of US-101 have the highest traffic density in the corridor, contributing to a less healthy environment and fewer travel choices for local residents.