Man. Reason #433 I’m happy I don’t live in Walnut Creek.
Come on, Chicago-area Dopers, isn’t anyone going to mention the Hillside Strangler? Eleven lanes converging from all points of the compass merge into three to form the Eisenhower Expressway to downtown Chicago. (Chicago, a metropolitan area with ten million people, has three-lane expressways.)
At the exact point of the merger, where traffic is guaranteed 24/7 to back up for miles, sits the most odious landfill in the Western Hemisphere, belching the methane gas of a million farts from decades of rotting garbage. The English language lacks words to describe the stench, and one gets to inhale it into every nook and cranny of one’s nostrils while advancing one car length per minute waiting for traffic to merge.
That was right around the time I stopped driving there. I always hated that thing. And yes, things were much better after that. What used to be a 90 minute trip from my parents’ house to the airport became 30 minutes.
Asheville, NC - I-40 and I-26 and the 240 circle interchanges. It’s certainly not as bad as many mentioend here, simply because there’s not as much traffic, but it gets pretty busy, with regular traffic jams.
This isn’t helped because the darn thing has near-blind signage going over hills, so you have only about 50 yards to switch to the lane you want to be in, which is likely to be the left lane, with no warning. And it’s amazing how much traffic little ole’ Asheville puts out. And the the city streets are freakish mazes of double-naming and mysteriously unmarked roads, going off in all directions.
And reason #444: Caltrans is scheduled to start a “rehabilitation” project on Hwy 24 between the Caldecott and 680 tonight. Think they said they’re going to put that on hold for a bit to see if traffic patterns and times change significantly as the work was scheduled to be done at night, for a whole bunch of weeks.
They use the same expression here: “The Kipling Avenue bridge will be rehabilitated over the next three months.” It always makes me imagine determined highway officials going out and lassoing drunken roads and bridges, tying them down and sobering them up, putting a nice new coat (of asphalt?) on them, and making them all presentable for the next driving season. 
Actually, it splits into five - You forgot 980
Also, I don’t know how many freeways are involved, but the “spaghetti bowl” in Las Vegas deserves at least an honorable mention. Considering how many people move to LV every month, this is (almost) as scary as the projected lack of water in the area.
It’s not so bad as long as you don’t:
Commute by car into San Francisco
Have to drive through the 680/24 interchange on a regular basis
Want to buy a home. They’re building some new condos a few blocks from our apartment. Condos that look like they’re pretty much the same as our apartment are going for a million bucks. This is probably the closest I’ll come to living in a million-dollar home for a good while…
The DC area had the worst traffic systems I’ve had to live with. The whole mess where 95 heads south from the beltway is a disaster. I lived in Annandale less then a mile from the beltway. I commuted daily to Fairfax. Every day I was thankful my commute was backwards. 66 eastbound was always a parking lot in the morning.
Boston is and always will be a complete clusterfuck. I grew up in the area and I’m thankfully very good at getting in an around Boston because of that. Driving in Boston is easy to understand. The guys who designed the roads hate you and every other driver on the road hates you. If your following directions, deviate from them and your screwed. As they like to randomly close roads and add on/off ramps in the wrong place you will probably have to deviate. Thankfully Boston is a very small city so if you get lost just pay 30+ bucks to park your car and wherever you want to go is a 10 minute walk.
I think NJ deserves a honorable mention. I hate NJ and their stupid divided roads that prevent you from ever turning left.