Page "Traffic" Paragraph 30

Countries party to the Vienna Convention on Road Traffic have uniform rules about overtaking and lane designation.

The convention details ( amongst other things ) that " Every driver shall keep to the edge of the carriageway appropriate to the direction of traffic ", and the " Drivers overtaking shall do so on the side opposite to that appropriate to the direction of traffic ", notwithstanding the presence or absence of oncoming traffic.

Allowed exceptions to these rules include turning or heavy traffic, traffic in lines, or situation in which signs or markings must dictate otherwise.

These rules must be more strictly adhered to on roads with oncoming traffic, but still apply on multi-lane and divided highways.

Many countries in Europe are party to the Vienna Conventions on traffic and roads.

In Australia ( which is not a contracting party ), traveling in any lane other than the " slow " lane on a road with a speed limit at or above is an offence, unless signage is posted to the contrary or the driver is overtaking.