Final answer:
When driving in the city, you should scan ahead for potential hazards at a distance allowing you to react safely, while in rural areas, you should scan even further ahead. It is not safe to cross the road if a car is only 28 meters away, as this provides insufficient time to cross safely before the car reaches you.
Step-by-step explanation:
When driving in the city, it's important to scan ahead for potential hazards. In towns and cities where the speed limit is typically around 60 km/hr, you need to be aware of your surroundings at a distance that allows you to react safely. If a car is 28 meters away, you should not attempt to cross the road as this distance is only equivalent to about eight car lengths, and a car covering 4 meters to safely cross in front of you is certainly within the risk zone at city speeds. In rural areas, where speeds can be higher and sightlines longer, scanning further ahead is necessary, potentially in the range of 10 to 15 kilometers at high speeds to allow for adequate reaction time to changes and potential hazards.
Regarding crossing safely, if a car is driving toward you and it is 28 meters away, it would not be safe to walk across the road. This distance is approximately the length of eight average cars, which does not provide enough buffer space to cross 4 meters safely before the car reaches you.