The 20 cities with the worst traffic in North America go far beyond Los Angeles

Thanks to the modern technology that allows cars to drive using signals bouncing off satellites, we now know more than ever before just how much time we waste in traffic. A new study by the TomTom navigation service says the average driver in America's largest cities spends 20 percent more time traveling during the rush hour than off-peak -- and that aside from the neverending snarl of Los Angeles, several cities on both coasts are seeing their driving time, and heart rates, on the rise.

By measuring the travel times of thousands of drives covering millions of miles in 26 U.S. and Canadian cities, TomTom says it was able to gauge not just how much time drivers in any given city spend in rush hour, but how that flow changes between different times and different days. The results show that the differences among the worst cities aren't as great as you might think; Los Angeles drivers lose an average of 40 minutes for every hour they spend on the road at peak travel, but in Seattle it's a still-stressful 35 minutes.

The TomTom North American Congestion Index

2012 Ranking

2011 Ranking

% delay from congestion

1.

Los Angeles

1

33%

2.

Vancouver

2

30%

3.

Miami

5

26%

4.

Seattle

12

25%

5.

Tampa

6

25%

6.

San Francisco

9

25%

7.

Washington, D.C.

4

24%

8.

Houston

18

23%

9.

Toronto

3

22%

10.

Ottawa, Canada

15

22%

11.

Atlanta

11

21%

12.

Montreal

7

20%

13.

San Diego

17

19%

14.

Chicago

19

19%

15.

New York

10

17%

16.

Calgary, Canada

13

17%

17.

Philadelphia

16

17%

18.

Dallas-Fort Worth

20

16%

19.

Boston

14

16%

20.

Baltimore

25

15%

TomTom's numbers do put some manageable figures to the purgatory of Los Angeles traffic. The average City of Angels resident with a 30-minute commute loses 92 hours a year -- nearly four days -- to traffic congestion. No city in North America suffers a worse backup in evening commutes, or sees its side roads slow down more under the burden.

Other cities are not that far behind. TomTom's study also covered Canada, and found that despite smaller populations, its cities were just as traffic-choked, with Vancouver worse than any U.S. city outside Los Angeles. The next four cities on the ranking -- Miami, Seattle, Tampa and San Francisco -- all suffer similar amounts of delay at rush hour. Only Tampa was not also among the cities with the worst increase in congestion, with Seattle gaining four percentage points of delay time from 2011 to 2012.

The least-congested city in TomTom's list? Minneapolis, where an hour in a peak commute will add an average of 16 minutes in delays, and where traffic moves at a relatively speedy average of 40 mph. Even with that relative brisk pace, Twin Cities commuters still spend a total of two days a year stuck in traffic. No wonder automakers think people might check Facebook and Twitter from behind the wheel. With that much time to waste, what else can they do?

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