Reaction time is the time it takes from you first recognize a hazard until you react accordingly. Reaction time consists of sensing, perceiving and then deciding what to do.

Normally, reaction time will be about 1-2 seconds, but it may increase, e.g. when

The traffic situation is complex.

Visibility is poor.

In unfamiliar situations or when you lack the necessary knowledge. In unfamiliar situations or when you lack the necessary knowledge.

Taking certain medications or intoxicants. Taking certain medications or intoxicants.

You are tired or for other reasons are having problems concentrating. You are tired or for other reasons are having problems concentrating.