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On the motorway



If you find yourself driving against the flow of traffic, pull in immediately to the hard shoulder and stop. Contact the gardaí by dialling 999. Do not attempt to turn your vehicle. Wait for help in a safe place.

Using lanes properly

It is very important that you understand the purpose of each lane on a motorway. To help explain how and when to move from one lane to another, each lane is given a number. The picture below shows that lane 1 is the lane nearest the hard shoulder. This is also known as the inside lane. On a two-lane motorway, the lane nearest the central median is lane 2 (also called the outside lane). On a three-lane motorway, this lane is lane 3.

Pic showing motorway. Lane one is to the left hand side (beside hard shoulder), lane 2 is middle lane, and lane 3 is outside right

Lane 1

The normal 'keep left' rule applies. Stay in this lane unless you are overtaking.

Lane 2

On a two-lane motorway, use this for overtaking only and move back into lane 1 when you have finished. You may also use this lane to accommodate traffic merging from the left.

On a three-lane motorway, you may stay in this centre lane while there is slower moving traffic in lane 1.

Lane 3

If you are travelling on a three-lane motorway, you must use this lane only if traffic in lanes 1 and 2 is moving in queues and you need to overtake or accommodate merging traffic. Once you've finished overtaking, move back to your left and allow faster traffic coming from behind to pass by.

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:

You may use it, however, in exceptional circumstances when you cannot proceed in the inner lane because of an obstruction ahead.

Keeping your distance

The Speed limits section 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.

When in a queue, your instinct may be to get closer to the vehicle in front to protect your position. Please remember that you must leave enough room in front of you to allow you to stop safely.


Once on a motorway, you must make a signal before every move. For example, moving from lane 3 to lane 1 involves two separate stages.

An indicator is not a right of way.

Before you start to manoeuvre you must exercise due care and attention with particular heed to other users of the road, prevailing road conditions and how your driving will impact other road users.

Checking traffic around you

Check your mirrors regularly, as you need to have a constant picture in your mind of what's going on all around you. Be very aware of your blind spots as well.

Avoid staying in other drivers' blind spots. Keep your eyes moving - avoid looking only at the vehicle immediately ahead. Instead, scan up the queue. Use your view to drive smoothly and avoid unnecessary braking. If you notice traffic slowing down sharply, use your hazard warning lights to warn traffic behind you.

Before changing lane, remember 'mirror, signal, mirror, manoeuvre'. Remember that traffic may be coming from behind you at speed. Checking your mirrors at least twice helps you judge this approach speed and will help you to see vehicles travelling in your blind spots.

Avoid causing another driver to brake or change lane to accommodate you while you are on the motorway (aside from joining it). Learn to read the traffic around you. A vehicle in your mirror on the motorway with its right indicator flashing is trying to tell you that it's catching up on you and intends to overtake your vehicle.


Overtake only on the right, unless traffic is travelling in slow moving queues and the traffic queue on your right is travelling more slowly than you are. If you intend to move from a slower lane to a faster lane, adjust your speed first.

Before you start to overtake, remember 'mirror, signal, mirror, manoeuvre', and look in your blind spots. Check that the way is clear (behind and ahead) and signal well in advance.

Remember that traffic will be travelling a lot faster than on ordinary roads. Be particularly careful at dusk, during darkness, and in poor weather conditions when it is more difficult to judge speed, distance and stopping distance. Signal and return to your original lane as soon as possible.


Gantries are structures used to display traffic signs above traffic lanes on motorways and dual-carriageways. They are common and display important information, so make sure you pay attention to them as well as to other signs along the side of the road.

Variable message signs

Variable message signs such as the ones displayed below are used on motorways to provide messages and information to motorists and to warn of incidents that may affect traffic conditions and journey times.

Motorists should pay attention to these signs at all times.

Overhead VMS Text

Typical LED VMS (continuous matrix)


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