Three lanes: the road context determines their use

The same diagram supports two different official theory-test rules. On a three-lane, two-way road, the centre lane is used only for overtaking. On a one-way carriageway with three lanes, vehicles may travel in parallel streams when traffic is heavy. The labels show the lanes, but the wording of the question identifies the road configuration. Always establish whether it describes two-way traffic or a one-way carriageway before choosing the rule.