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10. Boston
10. Boston

Congestion score: 14.7
Population density: 1,305.4 people per sq. mile (9th highest)
Average commute time: 29.2 minutes (tied for 10th highest)
Percentage driving to work: 76.6% (8th lowest)

It took commuters in Boston 14.7% longer to travel during peak hours than it would without traffic in 2012. This is more than double the nationwide congestion level. Among the major reasons for this was Interstate 93, three stretches of which ranked among the 50 most congested corridors in the nation. The interstate was rerouted from an elevated highway running above Boston to a tunnel running below the city as part of the area’s famous “Big Dig” project, which ran billions of dollars over budget and took decades to finish.

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The 10 U.S. cities with the worst traffic

July 31, 2013

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.