Drivers in Fort Collins, Colorado, can take another bow before calmly climbing behind the wheel. For the fourth time in a decade, Allstate has named it "America's Safest Driving City" in its annual analysis of car accidents.

Fort Collins has been in the top 10 every year, according to the insurance company, which assessed drivers in the 200 largest U.S. cities.

The most dangerous city to drive? Worcester, Massachusetts, which landed at No. 200 on Allstate's list. Massachusetts' second-largest city edged out the largest city in the state, Boston.

Allstate, which writes nearly one in 10 U.S. auto insurance policies, based its ratings on an analysis of claims data to determine the places with the greatest frequency of collisions, factoring in weather conditions, traffic volume, and population.

Get Breaking News Delivered to Your Inbox

The spread between the Fort Collins experience and that of drivers in Worcester is staggering. On average, a Fort Collins driver has an accident once every 14 years, about 30 percent less than the national average. In Worcester, the average driver crashes every four years or so. That's about 135 percent more than the national average.

Here are the top 10 U.S. cities with the safest drivers (see here for the full report).

Fort Collins, Colorado Brownsville, Texas Boise, Idaho Kansas City Hunstville, Alabama Montgomery, Alabama Visalia, California Laredo, Texas Madison, Wisconsin Olathe, Kansas

Here are the 10 least safe cities to drive, according to Allstate:

191. New Haven, Connecticut

192. Philadelphia

193. Alexandria, Virginia

194. Glendale, California

195. Baltimore

196. Providence, Rhode Island

197. Springfield, Massachusetts

198. Washington, D.C.

199. Boston

200. Worcester, Massachusetts