You must not use the lane nearest the central median, that is, the outside lane (Lane 2 or Lane 3, depending on the number of lanes), if you are driving: a goods vehicle with a maximum authorised mass of more than 3,500 kilograms, such as a lorry or heavy goods vehicle; a vehicle towing a trailer, horsebox or caravan; or a single or double deck bus or coach that is designed for carrying standing passengers.
It is a fixed-charge offence of up to €120 and 3 penalty points for a vehicle listed above to drive on the outside lane of a motorway (which may be Lane 2 or Lane 3, depending on the number of lanes).
You may use it, however, in exceptional circumstances when you cannot proceed in the inner lane because of an obstruction ahead.
A single or double-deck bus or coach that is not designed for carrying standing passengers may travel in the outside lane of a motorway and a driver of such a vehicle will not be guilty of an offence if they do so.
Auxiliary lane
These are normally identified by a broken white line to the right of the auxiliary lane, with markings that are shorter, closer and wider than the broken white lines normally seen in lane 1, 2 or 3.
When joining the motorway, you may use this lane to adjust your speed before entering (Lane 1), or you may stay in this lane if you intend to exit the motorway at the next exit.
If you do not intend to take the next exit off the motorway, you should join the main section of the motorway (Lane 1) to continue your journey.
If you are already driving on the motorway (Lane 1) and you intend to take the next exit off the motorway, you may then enter the auxiliary lane (Lane A).
If you are already driving on the main section of motorway (Lane 1, 2 or 3), you should not enter (Lane A) if your intention is not to leave the motorway at the next exit (unless instructed to do so by the Gardaí or Emergency Service personnel).
Keeping your distance
Section 8 covers the ‘two-second rule’ to help you keep a safe distance behind the vehicle in front. Use this rule on motorways – driving too close reduces your ability to stop safely, and significantly reduces your vision ahead.