Correct answer: A. To leave the motorway.
Auxiliary lanes are found on some motorways and are to the left of the main motorway lanes. They link the off-ramp of the road you are leaving with the next available off-ramp or exit. If a driver is already in lane 1 of the motorway and they intend to take the next exit, they should enter the auxiliary lane to do so. The auxiliary lane is normally identified by a broken white line to the right of the lane, with markings that are shorter, closer and wider than the broken white lines normally seen in lane 1, 2 or 3.
This is an official-style question from the Safe and Responsible Driving topic of the Ireland driver theory test (Cat. B). Practise all 807 questions free on iTest.ie — with timed mock exams, automatic mistake tracking and progress sync across devices.
Practise the full question bank free →