An annual ranking by Allstate says that drivers in Washington, D.C. are the most accident-prone of any U.S. city, getting in a collision every 4.8 years — more than double the national average, Bloomberg reported.

It's the sixth-straight year D.C. has held the designation. More congested streets are part of the reason Washington and other urban areas in the East fare worse than places in the West and South, said Kate Hollcraft, a spokeswoman for the insurer.

Allstate, the largest publicly traded U.S. auto and home insurer, publishes the annual analysis of its claims data to highlight safe-driving practices.

The cities that are along the East Coast are a little more compact,” she said in a phone interview with Bloomberg. “They’re older.”

Frankly, I'm not sure that flies. If congestion was the worst problem that causes a higher frequency of 'accidents', then New York City should top the list each year. But it's not even in the top 20!

Baltimore had the second-worst result, with drivers crashing every 5.4 years, followed by Providence, Rhode Island. New York motorists get in a collision every 7.3 years, the 23rd worst of almost 200 cities studied. Boston wasn’t included in the ranking because Allstate has limited data for the study period, which ran from January 2010 to December 2011.

Phoenix was the top-ranked city with a population of more than 1 million. Drivers there get in an accident every 9.8 years, Allstate said. Motorists in Fort Collins, Colorado, led the ranking with an average of 13.9 years between collisions.

The national rate of auto accidents has been declining for most of the past two decades as carmakers improve safety features, U.S. Department of Transportation data show.