Traffic Congestion

Daily Vehicle Hours of Delay Due To Congestion

Santa Clara & San Mateo Counties, Alameda County, Bay Area, and California

POLL TABLE: % Think Traffic Congestion is a Serious Issue

Bay Area, 2023

Female age 50+73%
No college degree69%
Hispanic, Latino/a/x/e, or Chicano69%
Black or African American68%
Male age 50+68%
Household income $20 – $99k68%
Working age, no commute59%
Asian / Pacific Islander58%
College degree57%
Household income $100k+56%
Tech worker54%
Full-time student48%

Data Source (chart):

Caltrans PeMS

Data Source (table):

Silicon Valley Poll


Silicon Valley Institute for Regional Studies

Data are from Caltrans PeMS (Performance Measurement System) which collects, filters, processes, aggregates, and examines traffic data from the Caltrans network of roadway traffic sensors. Data include California State Freeways only (not all state highways). Silicon Valley includes Santa Clara & San Mateo Counties. Bay Area includes the 9-County San Francisco Bay Area. The reported traffic delays data are based on the detector coverage and health at the time that the data was collected by PeMS. Accordingly, actual traffic delays experienced in each county may be higher than those reported. One vehicle hour of delay reflects one vehicle stuck in traffic for one hour. Delay refers to speeds less than 60 miles per hour. Data for 2012 through 2017 accessed December 27, 2021; data for 2018-2022 accessed January 26, 2023; data for 2023 accessed February 9, 2024. The share of Bay Area residents who think traffic congestion is a serious issue includes those who responded that it is “very serious” or “extremely serious”.

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Resources for Relevant Data and Reports (show)