Joining and leaving dual carriageways       Video

The acceleration [slip road ] lane is an extra lane on the left for use when building up your speed before merging with traffic on a dual carriageway so that you can join the flow safely.

 

 

The routine that you will use to join the flow of traffic on the main carriageway is the same as that you will use when joining motorways after you have passed your test

The routine for joining from a slip road is:

Mirrors and signal

Even though it should be obvious to other drivers that you are intending to pull out, a signal is useful because not everybody is as alert as they should be.

Watch for a gap

You need to assess the traffic as early as possible as you approach and look for a safe gap. Once you have identified the gap, concentrate on the car that you are going to follow.

Adjust your speed

Use the slip road to adjust your speed so it matches the traffic in  lane-one of the dual carriageway (the lane that you will be moving into). Too fast and you risk getting too close to the cat ahead; too slow and you will inconvenience following traffic.Joining

Just before moving into lane-one have a quick glance over your right shoulder. There is a possibility that a vehicle may be hidden in your blind spot. But be careful - this is just a QUICK GLANCE. You might be travelling as fast as 70 mph, you need to look where you are going! Look for speed limit signs, on a dual carriageway the National Speed Limit sign means a maximum of 70 mph.

Remember the basic rule for 'emerging' - only pull out if you are sure that it is safe and that you will not inconvenience other drivers.

At some dual carriageways you will leave via a an exit slip road, at others there will simply be a regular junction or perhaps a roundabout.

Deceleration lanes - exit slip roads; they allow you to slow down without holding up following traffic on the main carriageway. Usually, you shouldn't need to start braking until you enter the deceleration lane.

The routine for leaving via a slip road is:

 

Mirrors

Check your mirrors early, moving into the left hand lane about half a mile before your exit if you are overtaking.

Half mile warning sign for a slip road exit

 

On fast dual carriageways you will need to signal left much earlier than you would on other roads. Other drivers need plenty of warning about your intention to turn off.

Where there are countdown markers, signal at the three hundred yard marker (the one with three white bars) and maintain the signal until you have left the main carriageway. You might need to signal again if the slip road has a roundabout or other junction - if this is the case you need to go through the full MSM routine again

Position

Maintain speed and position (normal left lane position) until you reach the start of the deceleration lane. Check your mirrors again (all mirrors) and then move to the left to enter the deceleration lane.

It might be necessary to ease off the gas before joining the deceleration lane, however, unless the lane is particularly short, it shouldn't be necessary to use the brakes yet. If drivers behind are not responding to your signal a gentle touch on the brake pedal to activate the brake lights might be useful.

Speed

After joining the deceleration lane, use . If you have been driving for a while at high speed, check your Speedo - you might be going faster than you think. After a period of driving at a consistent high speed, 50 mph can feel like 30 mph

The routine for leaving via a left or right turn

Type of signs you could get for side road exit 

 

The routine for leaving via a left turn is:

Mirrors

Check your mirrors early, moving into the left hand lane about half a mile before your exit if you are overtaking.

Signal

Remember, other drivers need plenty of warning about your intention to turn off. The timing of your signal will depend on the prevailing traffic speed.

Position

Sometimes there will be designated turn lane , but often there will not. If there is no left turn lane, maintain your normal road position until the turn.

Speed

Your speed must be slow enough to turn safely, or to stop if their is an obstruction in the side road. You must also think about following vehicles - if another vehicle is following much too closely, you may have to slow down a bit extra on approach to give the driver behind time to react when you turn.

 The routine for leaving via a right turn is:                

Mirrors

 

Check your mirrors early, moving into the right hand lane about a quarter of a mile before your exit. It's important not to move to the right too soon because you might hold up faster moving traffic, on the other hand, if you are too late you will not have time to get safely into position.

Signal

 

Signal before moving to the right hand lane, remembering that other drivers need plenty of warning about your intentions on fast roads. Maintain your signal after changing lanes, others will need to know why you are in the right hand lane - if you cancel your signal, they might think that you are simply overtaking slower traffic - not expecting you to slow down.

Position

 

Move to the right hand lane early as described above. Sometimes there will be designated right turn lane

Speed

As with a left turn, your speed must be slow enough to turn safely, or to stop if their is an obstruction in the side road. Remember the following vehicles - if another vehicle is following much too closely, you may have to slow down a bit extra on approach to give the driver behind time to react when you turn.

Take special care when judging the speed of approaching traffic. Remember that you have two lanes to cross and that traffic will often be approaching faster than on two-way roads.

 Entering a Dual Carriageway from a side road turning left or right     Video               

           

 Entering a Dual Carriageway from a side road turning left

This is basically the same as an emerge to the left. There are some special considerations to take into account when emerging onto a dual carriageway though

All of the traffic on the dual carriageway will be approaching from your right but it is still important that you check to the left , it is good to know that you are safe before you move out.

While observing to the right do not just consider the near side driving lane. Traffic in the overtaking lane of the dual carriageway may well be changing back into the driving lane. Observe effectively until there is a suitable gap before moving off.

When you do emerge stay in the driving (left) lane We should always drive in the near side lane unless overtaking something or turning right.

 Entering a Dual Carriageway from a side road turning right

 

You will usually have to stop and assess the situation from the side of the dual carriageway.

The width of the central reservation of the dual carriageway is very important. You have to make the decision whether or not it would be safe enough for you to stop in the central reservation if you got half way across the dual carriageway and were unable to complete the manoeuvre onto the other side of the dual carriageway.

If the central reservation is narrow then you will not be able to use it in this way and will have to wait until their is a gap of sufficient size on both sides of the dual-carriageway that you can complete the manoeuvre in one go.

If the central reservation of the dual carriageway is wide enough then you wait until there is a gap from the right (and no right turning traffic coming from the left), make your way into the central reservation, and wait again for a gap from the left so that you can complete the turn onto the dual carriageway.

In either of the above circumstances it pays to remember that the gap in the traffic must be large enough that you do not affect the speed of the other road users because of your actions.

Turning right either across or from a dual-carriageway can be a dangerous manoeuvre if not completed carefully.

If the national speed limit of 70mph where in force then, if the road was clear and the weather conditions were good then that speed would be perfectly appropriate.

But the road may not be safe to drive at the maximum due to bends etc. judge your speed accordingly.

Keep a safe following distance by applying the two second rule . . .

"Only a fool would brake the two second rule".

Increase this distance in poor weather. You should normally stay in the left hand lane and only use the right hand lane for overtaking.

To make good progress you should overtake slow moving traffic when you are sure you can do so safely.

Overtaking        Video

Use the MSM routine when preparing to overtake.

Mirrors - always assess the speed and position of traffic behind (someone could easily be about to overtake you) you will need to check the interior mirror and the right hand door mirror.

Position - Keep well back, applying the 2 second rule. This will allow the vehicle in front to see you as well as keeping a safe distance.

Mirrors - Check again, always assess the speed and position of traffic behind , check the interior mirror and the right hand door mirror.

Speed - keep to the same speed as the vehicle ahead and consider changing down a gear for extra power to help pass briskly when you get the chance.

Look - assess the whole situation

the road conditions

the intentions of the driver ahead

any hazards (look out for signs)

Mirrors - re-assess the situation use the interior and right door mirror as you are about to overtake have a quick check for any blind spots - just a quick sideways glance (encase someone is in the process of overtaking you).

Signal - always apply a signal when going to overtake as this will help drivers behind and the person you are overtaking.

Manoeuvre - pull out on a smooth line overtaking as quickly as you can. Checking mirrors to make sure you are clear of the vehicle you are overtaking so that you do not cut them up when you return to the left lane. [ you should be able to see all of the front of the vehical you have overtaken in the rear view mirror ]

Apply a left signal and steer gradually back to the left lane unless you have other slow moving traffic in which case pass them before moving back to the left lane.

Diversion symbols that you  might get if the road is closed in an emergency  

      

 

                                         BACK TO TOP