Originally Posted by Protagonist
My defensive driving courses (I have to take refreshers every three years in order to drive a Government vehicle for work) used to call for a three-second following distance under ideal conditions. In the last refresher two years ago, that has been bumped up to a four-second following distance. Having ten defensive driving courses in the past 32 years of working for the Government, it has been interesting to see how the defensive driving rules have changed.
All of the refresher courses in the past decade say to add one second of following distance for EACH adverse condition. Rain or fog counts for two adverse conditions, because they combine wet roads with reduced visibility. Night is an adverse condition. Towing a trailer counts as an adverse condition. Gravel or dirt roads count as adverse conditions due to reduced traction (and dirt roads should also include reduced visibility for the dust cloud put up by the guy ahead of you).
So, by those standards, towing a trailer at night, in the rain, you would be up to a whopping eight-second following distance: standard four-second, plus one for night, one for trailer, one for rain, and one for wet pavement.
Also taught in the defensive driving courses— and a matter of common sense— one way to help ensure that your following distance is long enough, slow down. If you are going even just 1mph slower than the guy ahead of you, the following distance is always getting longer.
Of course -- as noted in another post -- being in or near to a metro area makes following distances more difficult. One has to continue to "lose position". Same for those stretches of Interstate between two cities less than 300-miles apart. One is hardly out of the traffic for one before the traffic for the other picks up. Which is why a low highway travel speed is best for towing.
I also highly value fuel economy, so the imposition of discipline onto an aid such as CC is not to use it based solely on mental impressions . . which can wind up being tossed aside by emotions. If I am out of the travel lane and into the passing lane, then CC is cancelled. Which means I am about to impose a FE [fuel economy] penalty. Is that worthwhile? (is the question to be asked every time).
Longest distance FE is based on the most miles in top gear and on CC. A travel speed that complements that combined use over the longest time and greatest miles (as above, in another post) is also consistent with decent travel speeds and separation distances. And is less stressful on driver and rig. A win-win all around when conditions allow.
notes above: generally, a travel speed of 55-65/mph will cover safety (and fuel economy): The most miles for the least fuel at the lowest risk
are goals I find compatible. And work towards.