Final answer:
The correct answer to whether you are allowed to open a door on the road side after parking is D, only if it does not interfere with traffic. It relates to safety practices for avoiding collisions, such as ensuring a safe distance from oncoming vehicles when opening a car door or crossing the street.
Step-by-step explanation:
When considering the question "After parking, are you allowed to open a door on the road side of your vehicle?" the most suitable answer is D: Yes, but only if it does not interfere with bicyclists and other traffic. This answer aligns with the concept of dooring, which is a traffic incident where a person inside a parked vehicle opens a door without checking for oncoming traffic, leading to potential collisions or injuries. Although there is no specific mention of the 10 feet rule as described in option B, being cautious about the surrounding traffic, which includes maintaining a safe distance and checking for oncoming vehicles or bicycles, is crucial before opening a door on the road side. Safety measures like the ones outlined in question details, such as allowing for more than the width of a car (including a safety buffer) before crossing a road, underpin the principle of not opening the car door into traffic without first ensuring it's safe to do so.