There's an interesting British thing where lots of people are militant about lane positioning to the point of recklessness. I know otherwise down to earth people who absolutely loss it when there's someone in the middle lane on a motorway. I have friends who will pull close behind the offending vehicle, flash their lights, beep their horn and yell - which is obviously far more dangerous than the original offence. This is in cases where there's a totally empty "fast" lane further to the right. Many drivers almost feel entitled to not have someone in front of them in the middle lane.
I get the argument for staying over to the left (in the UK). I'm not convinced that it's 100% rational though.
Picture a normal scenario with 3 lanes and on/off ramps coming in from the left.
With light traffic, all vehicles can keep to the left, over taking can happen in the middle lane and there's space for vehicles joining via the on-ramp. Fine.
With really heavy traffic, you normally end up with 3 lanes of traffic moving at increasing speed to the right and all the lanes are utilised. Everyone seems happy. Fine.
What happens with the murky space in between? If you try to stack everyone in the left lane they need to keep making space for people joining from the ramps. Also, some people will be moving faster than those in the far left, so they're effectively overtaking, but then where do you draw the line where they have to pull back to the left again (only to move out to overtake in another minute)? You could say that the moment there's any space to the left you move into it, but you just end up with lots more lane changes - which, at some point, becomes more dangerous than everyone just staying in the same lane.
There's a balance to strike between changing to satisfy the rule and staying the course to decrease the amount of changing. For different people that line is in different places and for a lot of people I know who grew up in the UK, if they place your behaviour on the wrong side of that (arbitrary) line, there will be hell to pay.
observations from austria (remember we have the steering wheel on the right side ... so, the left).
the law on the autobahn/multi-lane streets is: change to a lane on the left (a faster lane) only to overtake (except for special conditions, i.e. traffic jams/very slow moving).
mostly south of vienna, the system is different though. due to the high amount of traffic from eastern neighboring states, with different rules and different speed limits (austrias autobahn speed limit is 130km/h, while in the east it's sometimes 120km/h, i'd guess), it's usually:
* right lane (slowest): trucks and slow moving vehicles ~80-100km/h
* middle lane: normal traffic, depending on weather ~110-120km/h (with sometimes up to 130-140km/h if traffic permits, usually not for long though)
* left lane (fastest): traffic going faster (130km/h+)
you choose the lane appropriate for your speed. overtaking strictly on the left.
this is, strictly speaking, not legal. if the slower lane is free you have to change, even if you're going top speed.
in the beginning i've been complaining about people not observing the local laws, but nowadays i have to admit that i think the eastern system works better.
I get the argument for staying over to the left (in the UK). I'm not convinced that it's 100% rational though.
Picture a normal scenario with 3 lanes and on/off ramps coming in from the left.
With light traffic, all vehicles can keep to the left, over taking can happen in the middle lane and there's space for vehicles joining via the on-ramp. Fine.
With really heavy traffic, you normally end up with 3 lanes of traffic moving at increasing speed to the right and all the lanes are utilised. Everyone seems happy. Fine.
What happens with the murky space in between? If you try to stack everyone in the left lane they need to keep making space for people joining from the ramps. Also, some people will be moving faster than those in the far left, so they're effectively overtaking, but then where do you draw the line where they have to pull back to the left again (only to move out to overtake in another minute)? You could say that the moment there's any space to the left you move into it, but you just end up with lots more lane changes - which, at some point, becomes more dangerous than everyone just staying in the same lane.
There's a balance to strike between changing to satisfy the rule and staying the course to decrease the amount of changing. For different people that line is in different places and for a lot of people I know who grew up in the UK, if they place your behaviour on the wrong side of that (arbitrary) line, there will be hell to pay.
As a once foreigner it's all quite interesting.