Blind spot, can make you guilty of something that you couldn't see
Newer cars from our days have sensors on sides of the cars that can scan that close surrounding (blind spot) of a car where the driver can't see anything without turning the had to look over shoulder and avoid danger.
The blind spot is the space in between the outside view limit created by the side mirrors and the view angle of the human eye when looking forward.
This spot that can't be seen without turning the head is also names in many countries as a dead angle.
Unfortunately, not all the cars (actually most of them) have this helpful future to detect if something is into the blind spot.
And is as dangerous as the name is saying. Is a dead angle or blind spot because is not easy to see things there, (like an another car, bike, motorcycle) and not seeing them can lead to a collision, accident and even death.
The road code is saying that you as a driver are responsible to see things around you and you are also responsible for the blind spot.
In the situation of an accident, the driver that didn't see what is coming from this spot, is guilty.
This is the reason why, drivers are advice to turn their heads to check the side of the car where the move is about to happen, before doing the move, when joining a new road, changing lanes, or do an overtake.
Sometimes, on high speed, and on a busy road, turning head can be also dangerous. When you lose attention for even a fraction of a second from what is happening in front of you, a catastrofe can happen if the distance to the object moving in front of you is suddenly getting very small as fallow of a brake.
So, many times, before doing a move, you need to look over the shoulder and ensure the move is safe just before/after/same time, with checking the mirrors.
An experienced driver will always have a picture in his mind about what is around the car is driving. The distance the other cars have to himself, the speed of other vehicles around, if is any other object moving dangerous into the close proximity. And in case if something is not, as it suppose to be for a save drive, the driver will adapt speed, position, an even use the horn to make others driver aware of what is happening.
How to avoid the danger created by blind spot
The common sense says that if somebody in front of us is doing a dangerous move, like joining a lane without probably to see us, thirst thing to do is to anticipate that we are in the blind spot and/ or we have not been seen, and adjust our speed to let the other driver get in. In this way we will first avoid a collision and second you will save ourselves. We all can be sometime in the situation to do not see somebody in the blind spot. In the blind spot we are usually behind with a very small distance, less than half of a car length from the car in front of us, most of the time. Braking and adjusting speed are the most important things to do with the exception when our position will allow us to speed us a little bit and get in front of the other vehicle in time.
When driving on a motorway or 2 carriage road and when approaching to an entry, always try to let the first lane empty to the cars that are looking to merge into the traffic, and if possible, move to the most inside lane, if is not already busy. If it is, then keep a longer space between you and the vehicle in front of you to give the chance for an easy merging to any other driver is coming on your lane.
Never keep the same speed with the one of a vehicle joining the traffic if you realise that is going in parallel with you. Don't keep the same position because you can end being into the blind spot or simply making the join more complicated for the incoming driver which also have to adapt speed based of the cars already participant to the traffic. Adapting the speed to give more space to the incoming vehicle will save us from any other possible problem that can appear.