In traffic, the distance between your vehicle and the one in front of you is known as the safe headway. Keep a safe headway by ensuring you are at least two seconds behind the vehicle in front.
This is known as the two-second rule. You can use the following steps to check if you are obeying the rule:
On a dry road, choose a point like a lamp post or road sign.
When the vehicle in front passes that point, say out loud “Only a fool breaks the two-second rule”.
Check your position in relation to your chosen point as you finish saying this. If you have already passed the point, you are driving too close to the vehicle in front and need to pull back.
In wet weather, double the distance between your vehicle and the one in front of you by saying “Only a fool breaks the two-second rule” twice.
Remember, never drive closer than indicated by the two-second rule. If you drive too close to the vehicle in front (tailgating) and it brakes suddenly, you may not have enough time to react.
If you run into the vehicle, you will be liable for any damage caused.
Below is an excerpt from Drive Safe (A handbook for Western Australian road users).
You must keep enough distance behind a vehicle that will enable you to stop the vehicle
safely in an emergency – and without running into the vehicle in front.
Most rear end collisions are caused by drivers following too closely behind the
vehicle in front of them.
The space or ‘cushion’ between you and the vehicle in front of you is called the following
distance. To determine how much following distance you should allow, consider the
speed of the traffic and the condition of the road.
Two Second Rule
A way of estimating what is an adequate following distance is to use what is called the ‘two second’ rule.
While driving along the road look at an object by the side of the road, such as a tree or pole,that will soon be passed by the vehicle ahead. As soon as that vehicle passes the object, say to yourself, ‘one thousand and one, one thousand and two’. You should take the full two seconds it takes to say this to reach the object. If you get there before you have said it, you are too close.
Slow down until you are at least two seconds behind the vehicle ahead.
Remember that this ‘two second rule’ is a guide to use in good road, traffic and weather conditions. If they are not good, increase your following distance to
four or five seconds.