h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Generally, the rules listed in "United Kingdom: Motorway Driving Etiquette" apply. Just exchange right and left.
Naturally there are some local differences:

There is no general speed limit for cars. For lorries and everything on 4 and more wheels exceeding a weight of 3.5 tons, there is.
Which obviously forces every driver to leave the right lane for truck-use only - disregarding that the law requires you to drive on the right lane when you're not overtaking and independent of your cars speed. This is especially true for caravans, who never ever are allowed to use the right lane.
The left lane, on the opposite, is strictly reserved for 2 kinds of people:
1. Drivers of Mercedes, BMW and (grudgingly) foreign sports-cars. Preferably dark coloured. When you're driving a really fast car which happens to be another brand you can get away with it - if it's dark blue. If it's white, no chance.
2. Nice, balanced, wellmeaning drivers who want to introduce a speed limit (about 100-120 km/h) or simply detest speeding. They usually indicate right when they see somebody approaching fast in the rearview mirror - and switch the indicator off when the other car is nearly on their trunk. Without changing lanes, naturally. And purely as an educational measure, of course. They incidentally never dare "educating" when the approaching car is a dark Mercedes or BMW.
The real trouble starts when there are only 2 lanes, which usually leads to frenetic honking, repeated headlight-flashing and indicating on the left lane, while the right lane lies deserted apart from the lonely lorry now and then.

Overtaking on Motorways:
When you try to overtake somebody on the right lane, be careful not to exceed their speed by more than 5 mph.
When in a traffic jam, always change to the lane which goes fastest. Every inch counts, and it's not your fault that everybody tries to do the same. When there's no movement on any lane, use the hard shoulder, that's what it's there for apart from undertaking.
When you are driving a Mercedes or BMW (preferably dark blue), overtaking doesn't apply for you, because compared to your speed everybody else is not moving at all, so you are simply passing by. A different set of rules apply. And anyway, you have "right-of-way-integrated" ™ (which is valid in inner-city traffic, too). For you, speed limits which occasionally crop up on motorway, are never aimed at you.

Which leads over to: Speed limits and speed controls.
Always drive 20 km/h over the speed limit - 21 will cost your driving license and 19 will lead to a rapidly growing traffic jam behind you.
When realising that there is a speed control directly ahead, smile and wave for the picture that is about to being taken. Don't jam on the brakes - that only makes it probable that your license plate is readable on the picture. Using your hazard warning lights gives following drivers the possibility to adjust their make-up and hairdress or start yelling expletives when they've seen it too late.

I´d love to thank the driver of the silver colored -OF COURSE- Mercedes Benz owning the License Numer OB-UL xxxx (where "x" ist a constant, well known to me and within the range of the number between "7" and "9" --> NO KATS, not seven-OF-nine ) for his decision to prefer changing from the right to the left lane when I tried to cross the street due to MY green light. So it happened that I was not injured....A very very wise decision, I think. On the other hand - how the .... should he have been able to reduce his speed from about 80 km/h to zero ? Do I seem to be to much nitpicking ? I love life ! Well, every now and then a heart attack - who dares to mock ?