What is a dual turn?
Turning right onto a multi-laned road, and then a left turn shortly after; or
Turning left onto a multi-laned road, and then a right turn shortly after.
When making a right hand turn, as long as there is only one right turning lane:
turn into the left drivable lane (parked cars in the kerbside lane?)
indicate left for the left hand turn
This diagram illustrates that it is permissible to complete a right hand turn in either the right/centre lane or left/kerbside lane.
Image - RMS Road User Handbook, p.87.
When making a left hand turn, as long as there is only one left turning lane:
turn into the right/centre lane
indicate right for the right hand turn
If the information I have provided is confusing, I recommend you draw a multi-laned intersection and use a toy car to replicate the procedure, it may make more sense. This may also be a useful way to explain the procedure to your learner driver - communication is the key.
So, what has changed?
When you and I learnt to drive, we were required to complete a right turn onto a multi-laned road in the right or centre lane; and complete a left turn on a multi-laned road in the left lane.
Then we had the difficult task of trying to make the necessary lane changes across one or more lanes to get into position for our next turn shortly after - a difficult manoeuvre when fast moving traffic is coming up behind you on the road you just entered.
You are ready to make your second turn more safely.
When making a left dual turn, beware of any driver opposite you making a right turn. They may presume you will be completing your turn in the left lane and decide to turn right at the same time thinking they have a clear path into the centre lane - an illegal manoeuvre. The driver must give way to you, no matter what lane you turn into, unfortunately sometimes they don't.
Your only defence here is to look at the other driver and see which way they are looking. If their vision is focused on where they will be turning, and they are not looking at you, then there is a possibility they will not give way to you. Be prepared and careful; and make sure you and your learner driver have good vision habits in place so you can see the big picture.
Most test circuits will include a dual turn, and we find that this is one of the common things we need to work on with our more experienced learner drivers when they come to us for test preparation after long term home practice. It can be a difficult habit to change before the driving test.
It is best to get it right from the start when introducing turns at traffic lights.
If you have any questions regarding this topic, or any other road rule, please contact me. We are here to support your home practice and keep you all safer on the road.