Relatively recently, when I was trying to help my son move back home, I got stuck in traffic going to Milton Keynes.. just past Heathrow always gets congested.. we have a motorway famous for traffic delays.. it's called the M25 and it rings around London... some people call it the biggest car park in the UK as when it's bad you may as well park your car cos you aint moving anywhere anytime soon.. I think I was stuck about the same as you.. 2.5 hours.
It has three, sometimes four lanes for much of it.. the problem is just that it's way over capacity, the London area, and indeed the south west is the most heavily populated in the UK so simply there's just too much traffic.. probably wouldnt matter how many lanes they added - and there are restrictions on that around London anyway as again it's very heavily populated and lots of historical stuff :P lol if I ruled the world one of the things I would do in the UK is to share the business, the jobs etc more evenly.. the south west is over heated.. but in areas up north there are few jobs and much deprivation... ditts Scotland and Wales...
The M25 avoids the city too.. it's kinda a ring around London because going through London is even worse.. but there's just so much traffic in this part of the UK...and certain spots, especially Heathrow, (our main airport) get particularly congested.. and of course any accident entirely slows everythng up... It's ok when it's running smoothly, well except certain parts that are known to cause delays..
Re the 6 lanes in both directions.. well see you are thinking logically :P but here in the UK it's not that simple..we are a titchy country compared to the States.. so we just dont have the room always to do things like that...I think we are actually one of the most densely populated countries, (making no mention of immigration but it will impact) and we are one of the smallest... sooo I guess we have to put up with terrible congestion on the roads.
About 4-5 hours. It was a miserable trip. I was about 6 months pregnant with my youngest and my ex husband (then husband) and I decided to take the other two up to Flagstaff to see the snow. The first day was fine, but when we got up the next day, we heard that a huge snowstorm was coming in. We were kind of torn as to whether to try to make it out before it hit or attempt to get our same room for the night. We opted to try to get out, which was the wrong choice. They closed off all the roads out while we were on the freeway. We were at a dead stop for more than four hours... which was pretty miserable because my daughter (then 2) was coming down with a cold and I was miserable and pregnant.
There was nobody to tell us what was happening- just bumper-to-bumper traffic and no movement. Somewhere around the two-hour mark, I started calling hotels in the area, trying to get a room for the night, not even sure we'd be able to get off the highway. The rooms were all taken. The irony of a pregnant woman looking for lodging at Christmastime was not lost on us. I don't even think we got much beyond the city limits- say 10-20 minutes when we came to a full-out stop. The whole ordeal lasted about six hours- most of it just parked on the highway. We wound up in a crappy roach motel for the night, my daughter with a fever by that point. I have not taken a trip to see the snow since. -_-
That had to stink. The concept of driving to see the snow is still a little funny to me. I from the heartland...we don't drive to see the snow, it comes to see us. We had myself, my husband, 3 kids, my oldest's fiance and 2 grand babies (3 yr old and 4 months) Took 9:30 before we gave up and got a hotel. And we still 2 hrs away from our destination (a normal 5 hr trip)
The heaviest traffic I've seen was in LA. Before I was married I rode along with my then fiancee when he was a long distance truck driver. I remember he had to make two deliveries in the LA area and then go to the Central Valley to pick up fruits and vegetables the next day but when we left LA it was raining. I remember getting on 210 in Azusa and it was stop and go traffic all the way to Santa Clarita so it took like 2 1/2 to 3 hours to go that far.