The definition of a dual carriageway is a road with at least one lane of traffic (usually two or more travelling in the same direction) which is divided by a central reservation that separates it from the carriageway travelling in the opposite direction. Regardless of the amount of lanes, it will remain a single carriageway unless separated by a barrier.

 

Dual carriageways can be challenging for both experienced drivers and learner drivers. This is often due to the higher speeds involved and greater flow of traffic. 

 

Joining A Dual Carriageway From A Slip Road

You join many dual carriageways as normal from a T Junction, roundabout or crossroads. On some faster roads you may join the carriageway from a slip road.

 

The purpose of a slip road is for joining traffic to gain sufficient speed to equal those already on the carriageway. Joining the carriageway at 40 mph whilst traffic already on the carriageway is at a speed of 70 mph can be highly dangerous. 

 

Whilst accelerating, make quick checks to the right and into the right door mirror and alternate with the direction you are travelling. As you are accelerating, mark your entrance point in your mind - this is the gap you are going to fit into. This gap may require you to accelerate further or slow down to safely enter the carriageway.

 

Around half way down the slip road, you will need to apply the MSPSL routine. Check the interior and right mirror and signal to the right. Speed is dependent on the traffic on the carriageway and as you join you will need to look in your interior mirror to ensure traffic isn’t too close behind you or catching fast.

 

It is acceptable to join the carriageway a little too close to a vehicle in front of you that was already on the carriageway. However, if this is the case, you must increase the distance between you and the vehicle in front. This can be done by gently slowing down or overtaking the vehicle if it is safe to do so and you can keep under the speed limit.

 

Passing Slip Roads Whilst on a Dual Carriageway

As you are driving on the dual carriageway, other vehicles may also wish to join from a slip road. Keep an eye out for slip roads and other vehicles wishing to join. You do have right-of-way but you should make their joining as safe and easy as possible.

 

If you feel you may impede another vehicle joining a dual carriageway you may need to gently decrease speed or change into the right-hand lane by use of the MSPSL routine.

 

Exiting A Dual Carriageway Using A Slip Road

During a driving lesson, your instructor may say something along the lines of ‘I would like you to take the next exit’. Often, you will see countdown markers. The 1st one you see will have the 3 slashes signifying 300 yards from the exit. It is at this marker you should look into your interior mirror, followed by your left mirror and signal to the left.

 

DO NOT slow down on the dual carriageway. Use the exit slip road to reduce speed to the appropriate speed for the road or roundabout you will be joining.

 

Driving On A Dual Carriageway

Once on the carriageway, stay in the left lane and remember to keep a safe distance from vehicles in front. The 2 second rule may help with this. The speed limit of dual carriageways can vary and may be up to 70 mph. The examiner will be expecting you to drive at or close to the speed limit if possible and it is safe to do so.  

 

Dual Carriageway Overtaking

If you are behind a slow moving vehicle, you may wish to overtake it if possible. If you do, the MSPSL routine will need to be applied:

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Mirrors

Check the interior and right mirror and briefly check the right side blind spot to look for hazards in the right hand lane.

 

Signal

Apply a signal to the right.

 

Position

Keep a good distance behind the vehicle you intend on overtaking and move to the right only when it is safe to do so and you will not impede any traffic already in the lane.

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Speed

Steer to the right and once in the right hand lane accelerate past the vehicle.

 

Look

Once in the right lane, wait for the front of the vehicle you have overtaken to appear in your interior mirror, then check your left mirror, signal to the left and move back into the left lane. A quick check of the left blind spot may also be required.

 

Always drive in the left lane of a dual carriageway unless you are overtaking or turning right.

 

Quick Tips for Dual Carriageways:

• Make sure you accelerate on the slip road to match the speed of traffic already on the carriageway.

• Don’t slow down on a dual carriageway until you are on the slip road exit.

• Always follow the MSPSL routine when entering or exiting a dual carriageway from a slip road. Always apply the MSPSL routine when overtaking slow moving or parked vehicles in a dual carriageway.

• Be wary when passing slip roads entering a dual carriageway and make it ‘easy’ for those looking to enter by slowing down a little or moving into the right hand lane.