[geon]

Is it at all allowed to drive slow vehicles like tractors or scooters on a highway?

Here in Sweden, highways are off limits if the vehicle may not legally be driven faster than (i think) 45 kmph.

[Piskvorrr]

That's a bit of a "lost in translation" issue here: what is usually called a "highway" in Europe is usually a "freeway" in the USA. What we'd just call a "road" (pretty much any road) is called a "highway" in the US legal codes.

[Amezarak]

> what is usually called a "highway" in Europe is usually a "freeway" in the USA.

I think that usage is mostly West Coast. :)

Everywhere else, I've only heard "highway" or "interstate."

[maxerickson]

Freeway is fairly common in many parts of the US:

http://www4.uwm.edu/FLL/linguistics/dialect/staticmaps/q_79....

In common usage highway is still sort of reserved for larger connectors, road and street are used for local stuff.

[maxerickson]

In the US there are many roads with access limitations and minimum speeds, but many do not have those conditions.