Before You Make A Move
Lane changes might appear to be quite simple maneuvers, but can actually be one of the most dangerous if not done correctly.
Changing lanes usually means merging into other traffic travelling in the same direction. There are many factors to consider including blind spots, speed of other vehicles, detecting a safe gap and signalling correctly.
In fact there are so many factors to consider that it is not surprising that the main cause of lane change collisions is driver error.