Final answer:
You are permitted to open car doors on the side where traffic is moving only when it is safe and will not create a hazard. Safety precautions include checking for oncoming traffic and ensuring that opening the door will not endanger anyone.
Step-by-step explanation:
When considering when you are permitted to open car doors on the side on which traffic is moving, one must be extremely cautious and adhere to local traffic laws and regulations. In general, you should only open the door when it is safe to do so and when it will not obstruct or endanger traffic or pedestrians. The act of opening a car door into oncoming traffic can lead to dangerous situations, such as dooring accidents where cyclists or other vehicles collide with the open door.
For example, let's apply this knowledge to a situation where a pregnant woman is in the backseat experiencing labor and urgently needs to get to the hospital. Even though there is a need to act quickly, the driver and passengers must still ensure they are not creating additional hazards by opening doors into oncoming traffic, even if they are temporarily stopped at a traffic signal.
Ultimately, safety is the primary concern. Checking mirrors and over one's shoulder for approaching traffic before opening doors, as well as teaching all passengers to do the same, is crucial. Sometimes, even in non-emergency situations like driving to the grocery store or observing other drivers and pedestrians, awareness of simple acts like safely opening a car door is part of responsible vehicle operation and traffic interaction.