Living in the passed

Having driven quite often in South Africa, I realise the value of being able legally to overtake on either side on 3 or more lane roads. It makes lane hogging pointless and means much better use of road space. My local friends say it is not a cause of a greater than usual number of accidents. Back here I have tried to establish whether undertaking is illegal or not and I get conflicting answers, even from police officers. The consensus seems to be that it is legal, provided you do not keep changing lanes in order to do it. Is that right?

Asked on 9 January 2010 by JH, London

Answered by Honest John
It isn't illegal unless you are seen to be weaving in and out of traffic that might be deemed 'dangerous driving' by a police traffic officer observing your activity from a car or from the camera screens. But it’s perfectly fine to drive along the mostly unobstructed nearside lane of a motorway at 70mph passing all the idiots hogging lanes 2 and 3 at 60mph, taking car to watch out for any driver giving up and turning into that lane. The other drivers are in the wrong lanes, not you. And, of course, sometimes the dot matrixes over the M25 tell you to stay in lane due to congestion. You are not then compelled to brake because vehicles to your right have slowed down and you are passing them.
Similar questions
I drive a petrol Ford Focus mk1 which is 8 years old. When overtaking cars on I get to about 6,000 and then change gear. Would revving the engine to these revs damage the engine especially at the age...
Who is at fault if a car reverses from a parking bay into another car passing it.
I genuinely can't remember making a trip up a certain dual carriageway one morning in April 2017 when my car was photographed by a police camera travelling at 38mph. I have requested photographic evidence...
 

Ask Honest John

Value my car