British roads appear to be laid out in quarter mile strips connected by roundabouts, also known in Americanese as Traffic Circles. The roundabout is surely a hangover from the days when a horse-drawn carriages could not make a perfect 90 degree right turn. Or left turn. The British change slowly, very slowly. No need to simplify things for the motor car, not just yet.
Cannonballing down quarter mile stretches of road forces quick decisions. Your two lanes suddenly become three. Three lanes squeeze into the roundabout, where traffic is whizzing around it. The roundabout has No Lanes. Technically most roundabouts have two lanes, but no one draws lines and most drivers in a roundabout move through them in single file. Sometimes there is guidance. The signs tell you which lane you should be in. Sometimes not. But you can sure as hell bet that most of the locals are either complacent or as equally confused as you are. We all take the safe way out and stay in the left lane.
How could traffic be so fucked up in a modern country? How could two lanes become a swerving single lane on a modern road?
My only explanation is that there are not nearly enough guns nor litigation in the United Kingdom. (Here's a quote from Justin Webb's BBC piece: "A British man I met in Colorado recently told me he used to live in Kent but he moved to the American state of New Jersey and will not go home because it is, as he put it, 'a gentler environment for bringing the kids up.'" Thank you Howard Walker.)
In the United States there would be no such thing as the colossally fucked up roundabout known as Sadlers Farm on the A13, pictured below. Look closely at the satellite photo. That would be one giant roundabout which contains five, yes, five smaller roundabouts on it.
In the U.S., someone would have sued the governing body responsible for building that roundabout or there would have been so many shootings out of frustration and anger that the locals would have changed it.