According to
the American Highway Users Alliance
1999
1. Los Angeles, I-405 at I-10
2. Houston, U.S. 59 at I-610
3. Seattle, I-5 at I-90
4. Boston, I-93 Central Artery downtown at U.S. 1 known as the "Big Dig"
5. Washington, D.C./Maryland, I-495 at I-270
6. Washington, D.C./Virginia, I-95 at I-495 and I-395 known as the "Mixing Bowl"
7. Los Angeles, U.S. 101 Ventura Freeway at I-405
8. Los Angeles, State Route 55 Newport Freeway at State Route 22
9. Los Angeles, I-10 Santa Monica Freeway at I-5
10. Albuquerque, I-40 at I-25 known as "The Big I"
11. Atlanta, I-285 at I-85 in De Kalb County
12. Atlanta, I-75 at I-85
13. Chicago, I-290 at the junction of I-88 and I-294 called the "Hillside Strangler"
14. Denver, I-25 at I-225
15. Houston, I-610 at I-10
16. Washington, D.C./Virginia, I-66 at I-495
17. Washington, D.C./Maryland, I-95 and I-495 at the U.S. 1 to I-95 North junction
18. Atlanta, I-285 at I-75