Final answer:
In adverse conditions such as rain or snow, it's recommended to increase following distance to four to five seconds or more, considering both the driver's reaction time and longer braking distances. This allows for a safer driving experience and reduces the chance of collisions.
Step-by-step explanation:
When driving in adverse conditions such as rain, snow, or fog, it is crucial to increase the following distance beyond the standard three-second rule. The three-second rule applies to normal, dry conditions, but when road conditions worsen, stopping distances can become significantly longer. In wet conditions, for example, the stopping distance for a car traveling at 30.0 m/s can be considerably greater than on dry pavement, due to reduced tire traction and longer braking times.
To ensure safety, it's recommended to increase the following distance to at least four to five seconds when conditions are wet, and even more when conditions are particularly bad, such as during heavy rain, snowfall, or ice. This increased distance accounts for the longer stopping distance and the driver's reaction time, which remains constant at around 0.500 seconds before braking commences. By allowing more space, drivers have a better chance to react and stop their vehicle without colliding with the vehicle in front.
When planning to cross a road, it is necessary to account for the speed of oncoming vehicles and your ability to cross safely. For example, if cars are traveling at a speed limit of 60 km/hr and the average car length is 3.5 m, you should allow enough time to walk at least 4 m before the car reaches you. This takes into consideration your own reaction time and the distance needed to avoid the approaching vehicles.