Reaction Time: The Distance You Travel While Your Brain Is Thinking

Many drivers assume that when they see a hazard and decide to brake, the vehicle begins slowing immediately.

In reality, there is always a delay between the moment a hazard appears and the moment the vehicle begins to respond.

This delay is known as reaction time.

When something unexpected happens on the road, several stages must occur before the driver can act:

First, the brain must notice the hazard.

Second, it must understand what the hazard represents.

Third, the driver must decide what action to take.

Finally, the body must move — the foot presses the brake pedal or the hands turn the steering wheel.

Only after these steps does the vehicle begin to respond.

Even under ideal conditions this process takes time. During that time the vehicle continues travelling forward at its current speed.

For example, a vehicle travelling at 50 km/h moves around fourteen metres every second. If a driver’s reaction takes one and a half seconds, the car will travel more than twenty metres before braking even begins.

Nothing the driver does in that moment can eliminate this delay.

What drivers can control, however, is the distance travelled during that delay.

Lower speeds mean less distance is covered while the brain processes the situation. Higher speeds mean that the same delay results in a much greater distance travelled.

This is why speed management is so important.

Drivers cannot change how quickly the brain processes information. But they can change how far the vehicle travels while that thinking takes place.

Slowing down gives the brain time — and that time can make the difference between a near miss and a collision.