for major roads with more than one lane in each direction is very often a strip of grass seperating both directions. If not there's a solid central line. There should be also double solid lines, that are even stricter prohibiting crossing. But those are rare where i come from. It's quite a bit different here in america anyways, where even city roads have two lanes in each direction. (I always wonder why with such gigantically wide roads so many people relying solely on cars are so upset on bicycle lanes and trams.)
Oh yes, i forgot that you can turn from four lane streets into driveways. In germany if it is a four lane street it's for high throughput and you can only leave it at designated places, usually with trafic lights unless it is built for speed and has the equivalent of on ramps. (How do you call it in america if the highway is not elevated and it's not a ramp but an even way leading into the highway?)
So it's very tedious to prevent left turns? I usually tend to suggest to prohibit left turns in Toronto downtown altogether. It's a square grid, three right turns lead get you always to the same street and direction and the crossing traffic and right turns are fast at traffic lights. Only the left turners slow everything down. Especially the streetcars, for some reason the left-turners are allow to stand in their right of way when waiting for a chance to turn left. I always feel so terribly german when i watch the traffic here, with apparently less regulation but much less efficiency. I always have this very german notion comming up to tell everyone how to do it properly. I very much dislike when that happens.
(Oh and i hate american indicators, hardly visible! No bright amber light blinking, just a blinking backlight, or some inconspiciuously weak light at the front side difficult to discern from the headlight. Got some nasty surprises more than once here. Perhaps that's the reason why hardly anyone accelerates only
after leaving an intersection if they do it at all.)
[james on uk roads] short dashes indicate a faster road than long dashes
This is quite surprising and counterintuitive, since with higher speed the perceived length of the lines shrinks. (e.g. high speed german autobahn has 6 m dash with 6 m gap.)