Final answer:
On snow-covered roads, it is recommended to maintain a following distance significantly greater than the usual three-second rule, potentially eight to ten seconds, to accommodate longer braking distances on slippery surfaces.
Step-by-step explanation:
On snow covered roads, a good rule is to maintain a significant following distance to ensure safety due to potentially slippery conditions and increased stopping distances. In general, for most driving conditions, the three-second rule is recommended for a safe following distance, which should be increased to four seconds or more in poor weather conditions such as snow and ice.
In snowy conditions, a layer of ice may form under the snow, leading to hazardous road surfaces where the tires' grip is substantially reduced. It's crucial to maintain an ample gap to the vehicle in front since the coefficient of friction between the tires and the snow-covered road is reduced, leading to longer braking distances. The required stopping distance will also depend on factors like your speed, your vehicle's condition, and your reaction time.
Given these factors, if you're driving at 60 km/hr in snowy conditions, it is sensible to increase your following distance well beyond the normal three-second rule, potentially to even eight to ten seconds, to ensure enough time to stop or react to the unexpected. This can mean maintaining multiple car lengths between you and the vehicle ahead, as considerable distance will be necessary for your car to come to a safe stop on a snow-covered or icy road surface.