Undertaking should never be used as an excuse to change to outer lanes simply to avoid queuing and gain advantage. However, you can undertake a vehicle in slow-moving traffic queues, when the vehicles in the right-hand lane are moving more slowly. You can also undertake when the vehicle in front of you is signalling to turn right or when you are in a one-way street. In any event, undertaking must be carried out with caution and at reduced speed as drivers in outer lanes may not expect a vehicle to arrive alongside from the left. During the driving test, less than one in three (27 per cent) of learners get this right, making it the most commonly failed question. This may be due to the fact that, as soon as we hear the word ‘undertaking’, we assume it isn’t allowed in any circumstance.