There is a lot of confusion when merging. The old rule was to give way to the right even if the car on the right was a little behind us. That rule changed over 10 years ago but many people are still unaware.
Many people noticeably, do not understand what is required when approaching a Roundabout. For example many do not indicate at all, or indicate incorrectly. When exiting to the left approach cautiously, your speed ideally should be around 20 KPH if obstructions like trees, shrubs or a fence is evident.
Air Crash Investigator Experts painstakingly sift through remains of air crashes, to find out why the accident happened even if it takes years to find the cause, so adjustments and improvements can be made to help prevent future accidents from occurring. The trainee pilots require many hours in a Simulator that is programmed to cover all types of contingencies, before obtaining there wings.