George Carlin divided American drivers into two classes; those going slower than him were ****idiots; those going faster than him, **** lunatics. Another way to parse drivers is in a new study by Allstate Insurance has ranked the top 200 American cities by frequency of accidents, from best to worst.

The report grades cities by the collision frequency of those covered by Allstate insurance, and a two-year average is used to smooth out anomalies.

The safest cities to drive in, according to this report?

1. Ft. Collins, Colo. -- drivers average 14.5 years between collisions
2. Chattanooga, Tenn.
3. Boise, Idaho
4. Colorado Springs, Colo.
5. Knoxville, Tenn.
6. Eugene, Ore.
7. Reno, Nev.
8. Huntsville, Ala.
9. Lincoln, Neb.
10. Cedar Rapids, Iowa

At the bottom of the list:

1. Washington, D.C. -- averages 5.1 years between collisions
2. Baltimore, Md.
3. Glendale, Calif.
4. Newark, N.J.
5. Providence, R.I.
6. Jersey City, N.J.
7. San Francisco, Calif.
8. Elizabeth, N.J.
9. Los Angeles, Calif.
10. Jackson, Miss.

No surprisingly, a recent study by Tele Atlas found that most of the cities toward the bottom of the list are also among the most congested:

1. Seattle, Wash. -- 43% of roads congested
2. Los Angeles, Calif.
3. Chicago, Ill.
4. Montgomery County, Md.
5. San Francisco, Calif.
6. New York, N.Y.
7. Washington, D.C.
8. San Jose, Calif.
9. Alexandria, Va.
10. Oakland, Calif.

Among the list of most dangerous places to drive, Jackson, Miss., seems out of place, as the area is not known for exceptional congestion. Perhaps it can be explained by another Tele Atlas report, which found that Mississippi drivers had the highest average mph on rural and urban interstate highways, averaging 70.1 mph when the speed limit there is 65-70. In Nevada, with a speed limit of 75 and many flat, lightly traveled roads, the drivers only average 68.7 mph.