You might already know, but there is no specific offence that legally prohibits undertaking.
It's mentioned in the HC of course, and gives examples where it's acceptable, eg, to pass someone turning right, or when you are in a lane of traffic that is moving quicker than the adjacent right hand lanes.
However, a display of overt "undertaking" where you jump out of lane 3, into lane 2 accelerating past,many then back into lane 3 will see you cautioned or booked, under another specific offence (eg careless driving) (or dangerous driving if demonstrated to have caused an accident) especially where weaving/cutting back in is witnessed.
Interestingly though, in countries where undertaking is allowed (eg:USA) - I do think that the drivers on the freeway are in general much more aware of their surroundings (without Assists
) I only mention this because I have long wondered if we were to introduce undertaking in this country, would it force drivers to look more and be more aware of what's going on around them?
There are some other traffic laws I wish we could import from the USA eg: Right Turn on Red. So sensible.
This is one of the reasons why I do have a dashcam installed. If I were pulled up for a offence that involved a value judgement, I could reasonably demonstrate safe road use, along with any other mitigating circumstances.