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TRANSACTIONS NEWSLETTER ONLINE

July/August 2006

Facts & Figures:
Traffic Slows Down as the Bay Area Economy Speeds Up

If your drive to work seems to be taking longer than it did a couple years ago, it’s no illusion. Fueled in part by an expansion of the regional economy, commute congestion on Bay Area freeways increased last year at the fastest rate since 2000, according to data released by MTC in conjunction with Caltrans.

The daily number of vehicle hours of delay due to commute congestion in the nine-county region rose by 9 percent in 2005, following a modest 2 percent bump in 2004 and steady declines in congestion from 2001 through 2003.

Among the list of “Top 10 Bay Area Traffic Hot Spots,” the morning commute along westbound Interstate 80 from Hercules to the San Francisco-Oakland Bay Bridge retained its seemingly perennial hold on the top spot in 2005. In fact, the Bay Bridge and its ap-proaches accounted for three of the Bay Area’s 10 worst congestion locations for the second year in a row, including the eastbound afternoon commute across the span (number 10) and the afternoon approach on eastbound Interstate 80 and U.S. 101 in San Francisco (number 4).

Nine of the “Top 10” most congested freeway segments shared the same dubious distinction in 2004, although their rankings have been shuffled somewhat. The only newcomer to the list is the eastbound afternoon commute along State Route 4 from Bailey Road in Pittsburg to the A Street/Lone Tree Way exit in Antioch.

Vehicles typically spent about 135,700 hours a day in commute congestion on Bay Area freeways in 2005. While this marks a 9 percent increase over 2004 figures, it remains well below the 177,600 hours per day recorded in 2000 at the height of the region’s technology-charged economic boom.

At the county level, the biggest overall increase in freeway congestion in 2005 occurred in Contra Costa County, while Sonoma and Marin counties logged the largest percentage increases.
— John Goodwin

Top 10 Bay Area Traffic Hot Spots

Ranking of Commute-Period Bottlenecks Along Freeways, 2005
(Number 1 indicates the most congested freeway)

2005 Rank Location
(numbers correspond to map)		 2005 Daily (Weekday) Vehicle Hours of Delay 2004
Rank
1
 Interstate 80, westbound, a.m. — Alameda/Contra Costa County
State Route 4 to Bay Bridge metering lights
10,930
1
2
 Interstate 580, eastbound, p.m. — Alameda County
Interstate 680 to east of El Charro Road
6,100
3
3
 Interstate 580, westbound, a.m. — Alameda County
West of North Flynn Road to Airway Boulevard
5,830
2
4
 U.S. 101, northbound and Interstate 80, eastbound, p.m. — San Francisco
U.S. 101 from Alemany Boulevard to I-80;
I-80 from U.S. 101 to Sterling Street on-ramp
5,140
4
5
 U.S. 101, southbound, a.m. — Marin County
South of Route 37 to Interstate 580
4,490
7
6
 Route 4, westbound, a.m. — Contra Costa County
A Street/Lone Tree Way to west of Loveridge Road
4,000
6
7
 Route 92, eastbound, p.m. — Alameda County
Clawiter Road to Interstate 880 interchange
3,880
5
8
 Route 4, eastbound, p.m. — Contra Costa County
West of Bailey Road to A Street/Lone Tree Way
3,780
13
9
 U.S. 101, northbound, p.m. — Marin County
North of Marin City to Central San Rafael
3,690
8
10
 Interstate 80, eastbound, p.m. — San Francisco/Alameda County
Yerba Buena Island to Emeryville
3,120
10

Notes: Rankings are for routes in which continuous stop-and-go conditions occur with few, if any, breaks in the queue. Thus, corridors that have equally severe delays, but where congestion is broken into several segments, may rank lower in this type of congestion listing. Congestion is defined as average speeds below 35 miles per hour for 15 minutes or more. Source: MTC, Caltrans District 4

For a chart of daily freeway delay by county, click here.

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