Barely any city in the UK has a nice logical system (though Milton Keynes springs to mind) as most layouts go back centuries.
Most US highway junctions are nice sprawling affairs with pretty logical lane markings. The UK equivalent are often, shall we say, at best 'space constrained' and at worst confusing/dangerous. This is combined with lane widths that aren't generally as wide as the equivalent US roads, putting cars in closer proximity. The density of traffic in the UK is very high (it is a surprisingly small island, in case you hadn't noticed).
All this is not a good recipe for automatic, self drive robo-cars.
Oh, and trust me, UK drivers are in no way better than anywhere else (many should probably be using a white stick and a guide dog, while others will never go shopping for indicator bulbs).