When must you not pass a vehicle on the left at an intersection (if you can do so safely)? When must you not pass a vehicle on the left at an intersection (if you can do so safely)?

  • A. When the other car has stopped

  • B. When the other car is indicating right

  • C. When the other car is indicating left

  •  
    The correct answer is C
     
    If a vehicle is indicating left you must not pass it on the left as there's a risk it will turn into your path.
     
 
 
 

Passing a vehicle on the left at an intersection

You must not pass a vehicle on the left at an intersection if the vehicle is indicating to the left.

Some vehicles have to pull out to the right in order to turn left, whether at an intersection, driveway or mini roundabout, for example, large trucks and buses. Pay attention to the vehicle's indicators. Just because it moves out to the right doesn't mean it is turning right.

If you start to overtake the vehicle on the left and it turns in front of you, you are at risk of running into it.

This is particularly important for motorcyclists who can squeeze through smaller gaps, but they are at greater risk of falling under a vehicle's wheels in the event of an accident.

The same can happen for right turns. A long vehicle might stay left in order to be able to make a right-hand turn into a driveway or narrow intersection, or at a mini roundabout. 

Drivers are trained to look at their blind spots when making the final turn, but if you are on a cycle or motorbike you might not be visible as large vehicles have large blind spots.

The reason is to do with the circumference of the turn: the vehicle's front wheels will trace a wider arc than the rear wheels. The rear wheels follow a narrower arc (one with a smaller circumference) so if the vehicle doesn't pull out wider it risks the rear wheels running over the kerb or hitting road furniture or other vehicles. The amount of space needed to turn is called the turning radius, and the greater the wheelbase and the less the angle of steering, the wider the turning circle.

The same will apply for cars and motorbikes towing trailers.