No matter what city you go to, you're going to criticize its drivers because you, of course, are the greatest driver on the planet. However, D.C. is consistently rated among the worst—if not the worst—city for traffic. In 2013, the Texas A&M Transportation Institute's Urban Mobility Report ranked D.C. the most congested urban area, ahead of Los Angeles and New York, due to the estimated annual delay per commuter (67 hours) and additional gallons of gas wasted (32). The same study also calculated the amount of time drivers should allot for a commute that would take 20 minutes in light traffic: once again, D.C. was the worst with 114 minutes.
Be prepared to stew in your own anger as you sit in traffic, even if you've given yourself plenty of time to get where you're trying to go. During that time, you might consider taking the Metro—or moving to another city.