Across the nation, the typical American driver should expect to suffer some kind of car accident once every 10 years, according to the insurance companies which have to cut checks for those crashes. Yet that figure varies widely based on where you live, and by Allstate Insurance's tally, the city with America's worst drivers get into accidents twice as often as the national average -- and in the worst 10 U.S. cities, geography plays a big role in making driving more dangerous.

In its eighth annual report on traffic accidents, Allstate analyzed its claims data for 195 cities filed between January 2009 and December 2010 to determine how likely it was for a driver in those cities to get into a fender bender. For the fifth time, Sioux Falls, S.D. ranked as the city with the best drivers, who are 27.6 percent less likely to get into a crash than the national average. Close behind: Boise, Idaho; Fort Collins, Colo.; Madison, Wisc., and Lincoln, Neb.

While it would seem logical for smaller cities to have safer roads, and crash rates are generally worse in more populated areas, there are a few large cities -- namely Phoenix, Tucson and Indianapolis -- whose drivers outperform the national average. Philadelphia, Miami and San Francisco crack the list of 10 cities with the worst drivers, but are outpaced in wretched wheeling by several smaller towns.

Top 10 Cities With America's Worst Drivers

2012 Ranking 2011 Ranking Chance of accident vs. nat. avg. 1. Washington, D.C. 1 112% 2. Baltimore 2 88% 3. Providence, R.I. 5 81% 4. Hialeah, Fla. 11 78% 5. Glendale, Calif. 3 76% 6. Philadelphia 6 64% 7. Alexandria, Va. 10 63% 8. Newark, N.J. 4 59% 9. Miami 16 58% 10. San Francisco 9 55%

The real secret to having the worst drivers lies in geography. I live outside Washington, D.C., the city Allstate has identified as the home of the worst drivers in America for seven of the past eight years. It should be among the safest; the city has thousands of speed cameras, well-funded traffic police and has banned any use of hand-held cellphones while driving. But Washington's street layout creates dozens of six-way intersections featuring one road crossing at an unusual angle, turning below-average skills or aggressive drivers into a clear and present danger. According to Allstate, Washington drivers get into a wreck once every 4.7 years on average.

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Of the remaining nine cities with the worst drivers, five are East Coast towns whose streets were originally laid out for horse-drawn wagons rather than rip tides of two-ton SUVs traveling 50 mph. Even though California tops the Atlantic seaboard for traffic tie ups, only Glendale, Calif., and San Francisco crack the 10-worst list for accidents. Miami and its suburb of Hialeah, Fla., round out the list -- another example where drivers unfamiliar with roads play a starring role, although the average age of the people behind the wheel factor in as well.

It doesn't take a weatherman to know which way the wind blows, and it doesn't take a database of insurance claims to know bad drivers fill American roads every day. You can't control what other people do, but you can control what you do -- driving a little slower, being more careful, even extending some courtesy on the road. Or you could just move to Sioux Falls.

Photo: IntangibleArts via Flickr