Final answer:
A safe distance for crossing in front of a car should take into account the car's speed and visibility, with a recommendation of about five car-lengths to allow for adequate reaction and response times, forming a proper keep out zone.
Step-by-step explanation:
Determining the safe distance for crossing in front of a car depends on various factors such as the speed of the oncoming car and the visibility conditions. It's generally recommended to be cautious and ensure there's enough space for the car to come to a complete stop if necessary. As a rule of thumb, waiting for a gap that is equivalent to about five car-lengths can provide enough time for a pedestrian to evaluate the situation and cross safely. This distance allows for both the pedestrian's reaction time and the driver's response time, creating a sufficient keep out zone.