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3. San Francisco

3. San Francisco
Congestion score: 23.5
Population density: 1,754.8 people per sq. mile (3rd highest)
Average commute time: 29.2 minutes (tied for 10th highest)
Percentage driving to work: 71.4% (3rd lowest)

As many as 14.6% of workers in San Francisco took public transit to work in 2011, the third-highest rate of any metro area in the nation. Additionally, just 71.4% used a car, truck or van to get to work, the third-lowest percentage in the U.S. But despite the high public transit use, the area remained highly congested. Likely contributing to its high congestion is the area’s high density. The San Francisco area had the nation’s third-highest population density in 2010, with just under 1,755 people per square mile—behind only the New York and Los Angeles metro areas. In late 2010, the San Francisco County Transportation Authority decided to study whether charges would discourage drivers from traveling by car through highly congested areas during peak hours. A decision on implementing such charges hasn’t been made.

The 10 U.S. cities with the worst traffic

Last year, the average American driver wasted 38 hours sitting in

traffic. While the occasional traffic jam inconveniences most drivers,

some unlucky people live in the nation’s most congested cities. To determine the 10 cities with the

worst traffic, 24/7 Wall St. reviewed figures published by INRIX, a

traffic information and services group. The INRIX scorecard assigns an

index score for the 100 largest metropolitan statistical areas, and

individual road segments within those areas. Scores are functions of the

percentage difference between road segments’ uncongested (or “free

flow”) travel time and the calculated travel time on the roads during

peak hours. 24/7 Wall St. also reviewed population density from the 2010

Census, as well as travel time and commuting methods for each metro

area from the Census Bureau’s 2011 American Community Survey. All data

used were the most recent available. These are the 10 cities with the

worst traffic.