Final answer:
The first safe and legal rule when turning your vehicle is to signal your intention to turn. The discussion also touches upon Rule Utilitarianism, which might support breaking a traffic law under emergency situations to maximize utility, and the concept of ideal speed and safety distance in terms of car-lengths.
Step-by-step explanation:
If you are about to turn your vehicle, the first rule that is safe and legal is to use your turn signal to indicate your intention to turn, this allows other drivers and pedestrians to be aware of your actions and react accordingly. It is important to signal early enough before making the turn, giving sufficient warning to those around you. However, there are extenuating circumstances where rules can be bent, such as the urgent need to transport a pregnant woman who is about to give birth to a hospital. In such a scenario, the principle of Rule Utilitarianism (RU) might suggest that breaking a traffic law, like going through a red light at 4 AM when no other cars are present, could be considered morally acceptable if it leads to a greater good, such as ensuring the safety of mother and child.
In regards to the ideal speed for turning, it is the maximum safe speed your vehicle can turn on a curve without relying solely on the friction between the tires and the road. Knowing the ideal speed is vital for maintaining control of the vehicle during turns, especially in emergency situations.
When considering crossing the road in the presence of oncoming traffic, you should ensure there is a safe distance between you and the approaching vehicles. It is generally measured in car-lengths, and the exact number can depend on various factors including the speed of the oncoming vehicle and road conditions. Being cautious and overestimating the necessary distance is usually safer.