1. Washington D.C. I-95 south, exit 133A to the Fairfax County Parkway, VirginiaThis almost 6.5 mile section of southbound I-95 runs from south of the 495 Beltway to U.S Route 17 outside of Fredericksburg, Virginia, and was ranked the worst traffic hotspot in the nation with 1,394 traffic jams. As far as delays, that meant for 33 minutes traffic was traveling at least 65 percent slower than the posted speed limit. The estimated cost in lost time and wasted gas is $2.3 billion over the next 10 years, which is the highest in the country.