Question of the week: Is overtaking on the left illegal?

David Ross, Editor
Fri, 21 Mar 2025

Dear Honest John,

"I try to be a good driver and follow the rules, but frequently on motorways I find myself approaching a car in an outside lane going more slowly than me, even when I'm sticking to the speed limit.

It is irritating to have to move into the outer lane, wait for the driver ahead to move over, overtake and move back to an inside lane.

Is it actually illegal to undertake in this situation?"

- AJ

Dear AJ,

This is arguably one of those situations where the Highway Code doesn't quite cover the realities of modern driving.

It does offer some guidance however, which is pretty clear. Rule 267 states: "Overtake only on the right" while Rule 268 states: "Do not overtake on the left or move to a lane on your left to overtake."

However, it goes on to say that in congestion where adjacent lanes are moving at similar speeds you may keep up with the traffic in your lane even if this means passing traffic in the lane to your left.

It's also important to note that the rule states 'do not' rather than 'must not', which means there isn't a specific law prohibiting this action.

Even so, that doesn't mean you couldn't potentially be prosecuted for driving without due care and attention if a police officer happened to witness you undertaking outside of these circumstances, and there is always the risk that the boneheaded driver sitting in the outside lane while overtaking no one could decide to move left into your lane.

This issue could be solved by change in the law, but allowing passing on the left could mean irresponsible drivers blasting past you on the inside which is potentially much worse.

We would suggest undertaking is best avoided outside of circumstances where it is accepted in the Highway Code or otherwise unavoidable, however tempting it might be.

Ask HJ

Can you overtake cyclists on double white lines?

A short way from my home is a hill approximately 2 miles in length. There are double white lines in the centre of the road. There are lots of cyclists on the road, mostly in groups and commonly at weekends. Given that I need to keep 2 metres away from cyclists, technically, I cannot overtake them because of the double white lines. As one would expect, obeying the law, long queues grow. Some people do overtake cyclists and cross the double white lines. So, if the road ahead is clear and I were to be caught crossing the white lines by a policeman, would they book me or hopefully use some common sense and not bother.

Rule 129 of the Highway Code states the following: Double white lines where the line nearer to you is solid. This means you MUST NOT cross or straddle it unless it is safe and you need to enter adjoining premises or a side road. You may cross the line if necessary, provided the road is clear, to pass a stationary vehicle, or overtake a pedal cycle, horse or road maintenance vehicle, if they are travelling at 10 mph (16 km/h) or less. The speed of the cyclists is the key point here, so if they are travelling at 10mph or less you would be allowed to overtake safely.

Answered by David Ross

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