The rule 165 of the Highway Code of the United Kingdom (UK) is dealing mainly of many situations that the driver must not overtake a vehicle in front purposely to avoid road fatalities, thus protecting not only the life of the motorists but all other vulnerable road users.
The rule says that any driver must not overtake in these situations:
(1.) If you’ll have to straddle or cross the double white lines with one solid line nearest to you.
(2.) If you’ll have to enter a spot which is designed to divide traffic, and if it’s within a single solid white line that surrounds it.
(3.) The vehicle which is nearest to the pedestrian crossing and when it stops letting pedestrians to cross the road.
(4.) If you’ll have to enter an area which is reserved for trams, buses or cycles during its time of operation.
(5.) Beyond a “No Overtaking” sign and until you will pass a sign that cancels the restriction.
Also, don’t overtake if there’s any doubt, or where you cannot see far enough ahead to be sure it is safe. For example, when you’re approaching the following:
(1.) a corner or bend
(2.) a hump bridge
(3.) the brow of a hill.
Don’t overtake if you think you might be in conflict with the other motorists or road users.
For example: When you’re:
(1.) going to approach a road junction or if you’re already on it at either road side.
(2.) in an area where the road ahead narrows or when you’re in a narrow portion of the road.
(3.) going to approach a school crossing.
(4.) in between the kerb and a tram or bus when it is at a stop
(5.) in an area where there is a long queue of traffic at road works or junctions.
(6.) going to force another motorist to slow down or swerve.
(7.) at a level crossing which is currently functioning that anytime unexpectedly trains are passing by.
When a road user is indicating right, even if you believe the signal should have been cancelled. Do not take a risk, wait for the signal to be cancelled. Because there may be reasons you don’t know why the signal continues even if the car is still going straight ahead at the moment but surprisingly will turn right quickly for an emergency.
If you are a defensive driver, you will think that it’s better to waste a few minutes waiting for the signal to be cancelled and just stay behind rather than overtaking aggressively only to collide with that vehicle in front which turns to the right quickly according to its given signal.
On the other hand, if you are following a cyclist, stay behind him or her when approaching a roundabout or junction, and you intend to turn left. Many drivers aren’t willing to do this because the pace will be very slow to waste more of their time, so they have the tendency to overtake the cyclist before reaching the corner, thus raising the risk of an accident.