Two gripes after a 12 day road trip.

[retread]

72. 3 second rule? For day light and good conditions,

"To determine the right following distance, first select a fixed object on the road ahead such as a sign, tree or overpass. When the vehicle ahead of you passes the object, slowly count "one one thousand, two one thousand, three one thousand." If you reach the object before completing the count, you're following too closely. Making sure there are three seconds between you and the car ahead gives you time and distance to respond to problems in the lane ahead of you."

" In heavy traffic, at night, or when weather conditions are not ideal (eg. light rain, light fog, light snow), double the three second rule to six seconds, for added safety."

"If the weather conditions are very poor, eg. heavy rain, heavy fog, or heavy snow, start by tripling the three second rule to nine seconds to determine a safe following distance."

This means at 65 mph and using the 3 second rule you should have 288ft between you and the vehicle in front. At 6 seconds the distance is 576ft.
At 75 mph the distances are 333ft and 666 ft.