First Freeway Congestion Report Since 2009 Reflects Bay Area's Economic Resurgence

Jan. 9, 2015
Vital Signs Initiative revives "Top 10" congestion list.

The Metropolitan Transportation Commission (MTC) on Jan. 9 released its first comprehensive report on Bay Area freeway congestion since 2009, providing another concrete measure of the region’s recovery from the Great Recession.

“Congested delay,” which the commission defines as time spent in traffic moving at speeds of 35 miles per hour or less, rose 18 percent in 2013 to an average of 2.6 minutes per commuter each weekday in 2013 from 2.2 minutes in 2012.  This marks the Bay Area’s highest level of congested delay on a per-commuter basis in at least 15 years and a 37 percent increase over the average 1.9-minutes-per-commuter-per-day figure registered in 2010 at the nadir of the region’s recession-fueled traffic break. “Total delay,” which MTC defines as all time spent in traffic moving below the posted speed limit, averaged about 7 minutes per commuter in 2013. 

The freeway congestion report is the first of dozens of performance measures to be released by MTC over the next few months as part of its new Vital Signs initiative, which focuses on tracking regional performance for key transportation, land use, environmental and economic policy goals identified in Plan Bay Area, the long-range transportation and land use plan adopted by MTC and the Association of Bay Area Governments in 2013.

MTC’s previous freeway congestion report, released in May 2009, included data from 2008. The five-year gap in reporting congestion statistics is due to a change in data collection methods. The Commission used to hire consultants to conduct what are known as floating-car runs, where teams of drivers would travel various freeways at select times on select days and measure the time during which speeds fell to 35 miles per hour or less and then multiply that time by the number of vehicles counted in a particular corridor.

“By 2009, we were looking for ways to not only reduce our data collection costs but to get more detailed information from all the region’s freeways at the same time,” explained MTC Chair and Orinda City Councilmember Amy Rein Worth.  “We eventually contracted with a company called INRIX that collects traffic data not just from traffic cameras and roadway sensors but also from automakers’ in-vehicle GPS systems, fleet operators’ vehicle-location devices, mobile providers and other sources to deliver a nearly constant, 24-hour stream of information.”

Big Changes in Top 10 List

Among the notable findings from MTC’s Vital Signs analysis of the 2013 freeway congestion data — and from the updated data collection methods — is a big shakeup in the "Top 10" list of congestion hot spots over the past five years. The eastbound Interstate 80 commute in the afternoon from U.S. 101 in San Francisco out to Yerba Buena Island moved into the top spot with an average 6,900 daily vehicle hours of delay and average speeds of just 4 mph at the peak of the commute. This was the Bay Area’s eighth most congested commute corridor in 2008. Meanwhile, the morning commute along westbound Interstate 80 from State Route 4 in Hercules to Emeryville, which ranked #1 throughout the early 2000s, dropped three places to #4 in 2013, with 5,000 daily vehicle hours of delay and average peak period speeds of 16 mph. The silver medal spot on the 2013 list is the southbound morning commute on Interstate 880 from Interstate 238 in San Lorenzo to Dixon Landing Road near the Alameda-Santa Clara County line, with 5,600 vehicle hours of delay. Third place on the 2013 congestion list goes to the afternoon commute on southbound U.S. 101 from Fair Oaks Avenue in Sunnyvale to the 13th Street/Oakland Road exit in San Jose. Rounding out the top five is the afternoon commute in Contra Costa County along northbound Interstate 680 from Bollinger Canyon Road in San Ramon to Treat Boulevard near Pleasant Hill. 


The morning commute on westbound Interstate 580 from the Alameda-San Joaquin county line to the Fallon Road/El Charro Road exit between Livermore and Dublin ranked #6 on the 2013 list, the same position it held for 2008.  The biggest mover on the 2013 list is the afternoon commute along northbound Interstate 680 from South Mission Boulevard (State Route 262) in Fremont to State Route 84 in Sunol, which jumped to #7 from #31 in 2008. The eighth most congested corridor for 2013 is the afternoon drive on eastbound Interstate 80 from West Grand Avenue near the east end of the Bay Bridge in Oakland out to Gilman Street in Berkeley. The remainder of the Top 10 list includes the afternoon commutes on eastbound State Route 24 from 27th Street in Oakland to Wilder Road on the Orinda side of the Caldecott Tunnel (#9) and northbound U.S. 101 from Woodside Road (State Route 84) in Redwood City to Hillsdale Boulevard in San Mateo (#10).

“A few things really stand out when you look at the regional data,” explained Rein Worth. “One is that congestion is highly concentrated in a select few freeway corridors, primarily in the inner Bay Area and on routes leading into or out of our two biggest employment centers, San Francisco and the Silicon Valley. Another is that more than half of the region’s congested delay is found on freeways in Alameda and Contra Costa counties. And a third is that commuters on many of the region’s most congested corridors stand to benefit as major investments such as BART to San Jose, BART capacity improvements, Caltrain electrification and new freeway express lanes come on line in the years ahead.” 

The Bay Area’s first express lanes opened in 2010 on southbound Interstate 680 in Alameda and Santa Clara counties, and in 2012 on State Route 237 in Milpitas and San Jose. The region’s next express lanes are scheduled to open late this year on Interstate 580 in the Tri Valley area of eastern Alameda County, followed by the planned 2017 opening of express lanes on Interstate 880 in Alameda County as well as the East Bay approaches to and from the Dumbarton and San Mateo-Hayward bridges.  Express lanes can be used free of charge by carpoolers, buses and motorcycles, and also are available for use by solo drivers who choose to pay a toll that varies according to congestion levels.

A complete list of the 139 most-congested Bay Area freeway segments will be posted Jan. 28, when MTC unveils its Vital Signs website. This interactive online tool will allow residents to track the region’s progress toward reaching key transportation, land use, environmental and economic policy goals. It will illustrate historical trends, differences and similarities among various Bay Area communities, and how our region stacks up compared to other major U.S. metro areas.