Final answer:
The 'three-second plus rule' is true and it is a method to ensure safe following distance while driving. The rule accounts for driver's reaction time and specific road conditions, which affect the total stopping distance of a vehicle. It's essential for road safety and pedestrian awareness in traffic situations.
Step-by-step explanation:
The statement about the "three-second plus rule" is true. This rule involves measuring the distance by choosing an object along the road, such as a sign or a pole, and counting the seconds it takes to reach the same spot the car in front of you has just passed. Ideally, this time should be at least three seconds. Bridget's observation from her classroom window that most cars take 3 seconds to travel between two poles 50 meters apart indicates that they are maintaining a distance that allows for safe stopping. In addition to reaction times, stopping distances can vary depending on road conditions and the vehicle's initial speed, as shown in various figures discussed.
For example, if a car is initially traveling at 30.0 m/s, the total distance needed to stop will include the distance covered during the driver's reaction time plus the braking distance, which is longer on wet pavement compared to dry pavement. When crossing the road, considering the speed limit in towns and cities and the average car length, to cross safely, you should ensure that you can walk at least 4 meters before the car reaches you. This calculation provides a general sense of the safety measures one should take concerning vehicle speed and pedestrian crossing.