Final answer:
You should dim your headlights when within 500 feet (150 meters) of oncoming traffic at night to prevent glare and ensure safety. The exact distance can vary by local traffic laws. Safety considerations for crossing the road depend on car speed and other conditions.
Step-by-step explanation:
When driving at night and approaching oncoming traffic, it is necessary to dim your headlights to prevent glare and ensure safety for both you and the other drivers. This is because the bright light from the headlights can temporarily blind the other driver, making it difficult for them to see the road ahead. The specific distance at which you should dim your headlights can vary by jurisdiction, but a common rule of thumb is to dim them within 500 feet (150 meters) of an oncoming vehicle. However, always consult your local traffic laws to comply with the specific regulations in your area. Regarding the question of how far away a car must be before it's safe to cross and the number of car lengths this equates to, it depends on various factors including the speed of the car, the road conditions, and visibility. A safe rule is to ensure the car is far enough away to allow you ample time to cross safely, which might be around 8 car lengths or more, but this is a rough estimate and safety should always be the priority.