Eric Thompson: Back off, there's a good chap

That nice, airy space between moving vehicles ensures they can all stop without ploughing into each other. Photo / Janna Dixon

I would dearly like to know why some drivers think the gap you leave between the car in front of you at 100km/h for safety reasons, was purpose-built for the selfish sods to park their car in?

You know what I mean: you're travelling in a line of traffic, using the two-second rule, when all of a sudden some sod flies up the inside lane and inserts themselves in front of you.

You hit the brakes, causing the tailgater behind you to do the same and start to fishtail. Now everyone is slamming on their respective brakes causing the previously free-flowing traffic to dislocate - puzzling the driver 2km back. And all because some idiot doesn't know the two-second rule, which is as follows, according to the NZ Transport Agency.

* It's important to make sure you have a safe distance between you and the vehicle in front, so you will have enough time to stop if you need to stop suddenly.

* Under normal conditions, the two-second rule is an easy way to make sure you have allowed enough following distance between your vehicle and the vehicle in front, no matter what speed you're travelling at.

To check if you are travelling two seconds behind the vehicle in front:

* Watch the vehicle in front of you pass a landmark, such as a sign, tree or power pole, at the side of the road

* As it passes the landmark, start counting "one thousand and one, one thousand and two".

* If you pass the landmark before you finish saying those eight words, you are following too closely - slow down, pick another landmark and repeat the words to make sure you have increased your following distance

It's not rocket science.

I find it especially odd, and even infuriating, when a driver following pulls into the inside lane, accelerates past, then pulls into the gap and sits there for kilometre after kilometre because we are in a line of traffic. What on earth is the point of passing me just to sit 20m further ahead in the same line of traffic?

I did once, though, rather than get wound up, keep pulling back leaving a gap and counted eight cars pull exactly the same stunt. I passed them all again much later on a tight uphill section of road that had a passing lane because they all slowed to crawl around the bends.

Any driver who thinks they have the reaction times of an F1 driver when something happens in front of their car would, in fact, be driving in F1 - not on a motorway here.

So, take note, when drivers leave a two-second gap it's because we want to get home safely and see our families.