Averaging 81 Miles Per Hour

cars.com's KickingTires blog lists the fastest traveled roads in the United States during 2011 according INRIX, a traffic data firm that tracks GPS data. The average speed this year on the ten fastest roads in America is 81 mph, down from 85 mph last year. Here's the top five fastest roads in reverse order including the average speed, highest speed clocked and distance:

5. Arizona State Route 77
Northbound out of Tucson to the AZ-76/Redington Road interchange near San Manuel Airport
Average speed of fastest 5%: 81 mph
Top speed clocked by INRIX: 81 mph
Length of corridor: 4.8 miles

4. Eastbound MI-5 Michigan Highway
Heading into Detroit from the I-275/I-96 interchange to Telegraph Road
Average speed of fastest 5%: 81 mph
Top speed clocked by INRIX: 83 mph
Length of corridor: 4.9 miles

3. California State Route 73
In both directions between Moulton Parkway and Bear Street
Average speed of fastest 5%: 81 mph
Top speed clocked by INRIX: 85 mph
Length of corridor: 14.8 miles

2. Oklahoma State Highway 33
In both directions just Northwest of Oklahoma City
Average speed of fastest 5%: 83 mph
Top speed clocked by INRIX: 87 mph
Length of corridor: 24 

1. Northbound Arizona State Route 79
Between Saguaro National Park and Phoenix
Average speed of fastest 5%: 88 mph
Top speed clocked by INRIX: 94 mph
Length of corridor: 17.6 miles