Final answer:
You should maintain enough space between you and the vehicle in front to allow for safe stopping in case of an emergency. The ability to safely cross a road depends on several factors including the approaching vehicle's speed, your walking speed, and the distance to the vehicle.
Step-by-step explanation:
As a general rule, you should always have enough space between you and the vehicle directly in front of you to ensure safety. In town and city environments where the speed limit is commonly 60 km/hr, and the average car length is 3.5 m, a safe following distance is crucial for emergency situations. This buffer allows you time to react and stop to avoid potential collisions.
If you see a car driving toward you, and it is 28 m away, this is equivalent to the length of 8 cars. Based on the recommended safe distance, this may not be sufficient for you to safely cross the road on foot, especially considering your own walking speed and the approaching car's speed. Immediate judgment is critical, and when in doubt, it's best to wait until the vehicle has passed or there is a clearer safe gap.
In the scenario with an ambulance, the best action to take is to stop moving and become stationary till it passes by. Running alongside or toward the ambulance is unsafe and could result in an accident.
For a car traveling in the furthest lane from an observer, the observer's ability to cross all 3 lanes of the freeway safely depends on various factors including the car's speed, the observer's walking speed, and the distance between them. Proper estimation of these distances and speeds is paramount for safety.