Didn't see this one coming - water off the roof of an RV in a corner!

[Howie]

. 

Where on earth did you get 5 seconds from?

It's two seconds.

5 seconds was a typo.  It should have read 2 seconds. 

[r_ciao]

For car driving, the rule is 3 seconds.  It doesn't matter what the speed is.  It's just 3 seconds.  It used to be 1 car length for every 10 mph, but some drivers cannot figure this out when driving due to their depth perception or b/c they are just plain dumb.  It's much easier to pick a stationary object such as a light pole or street sign and count from there.  That being said, bikes brake quicker and may need less time (2 seconds?).  Either way, ride safe or at the least, ride safer. [moto]

[ScottRNelson]

For car driving, the rule is 3 seconds.  It doesn't matter what the speed is.  It's just 3 seconds.

So who says 3 seconds is the correct amount?

Who is the expert claiming this?

The safe driving courses have been teaching two seconds for decades and two seconds has always worked well for me as a safe following distance.  So who has changed it to three seconds and why?

[wbeck257]

So who says 3 seconds is the correct amount?

Who is the expert claiming this?

The safe driving courses have been teaching two seconds for decades and two seconds has always worked well for me as a safe following distance.  So who has changed it to three seconds and why?

Anyone who has ever taken the "Smith System" driving courses will tell you 3 seconds.
I've worked at several jobs (all Fortune 500 companies) where driving ed is part of training, all of them you take Smith System.

http://www.smith-system.com/
They claim they are the "global leader in driving training"...

[Howie]

As the US population is aging the magic number is changing from 2 to 3 seconds.  Blame AARP

[tangueroHondo]

After I started this thread I began paying more attention the distance time thing.  I actually took out the tape measure and measured different distances in a parking lot to give perspective. 

I also recently bought the new Hough motorcycling book and have been reading that off and on.  Bottom line isn't really pinpointing a specific time or distance for following:   A person has to be prepared for what 'might' happen.  The mistake would be to assume that we know what will happen (i.e. that the car in front of us will continue to drive the same speed) when we know that we do not know (i.e. the car suddenly brakes hard for a squirrel crossing the road in the middle of a corner).  Isolating following distance to 2 or 3, 4 or 10 seconds would be a mistake.

[red baron]

sounds like condensation from the roof-mounted air conditioner.

Or they washed it. 

[Shortie]

I felt completely comfortable with the room one second prior to that. 

In my opinion, if you are completely comfortable with what is going on around you you're looking for trouble. I haven't been riding for long but I learned right away that complacency is dangerous. 2-3 seconds may be acceptable in perfectly ideal road conditions, but how often are conditions really ideal? 3-5 seconds may give you enough time to react to something immediately in your path if you are caught off guard, but that isn't nearly enough time to anticipate a hazard.

Why would you want to put yourself in a position of having to execute an emergency maneuver, instead of being prepared for a situation before it becomes immediate? I do realize each situation encountered on the road is different, some factors just cannot be controlled, and this isn't meant to be a blanket statement by any means. But considering some of the most common reasons for single-vehicle fatalities and injuries - failure to negotiate turns prior to crashing, speed, collisions with fixed objects, improper/late braking and steering maneuvers, etc. - why wouldn't you want to put a nice cushion between yourself and what's in front of you to save your own ass?

Again I'm still a noob and more intuitive veteran riders may disagree with me, but I have found the above to be true at least in my own personal albeit limited experience.