Based on research - how an accident occurs

A traffic accident is an event that occurs instantaneously. This is what an event evolves and develops in two physical dimensions, ie in space and time.

These phases should be valued at the time at which a driver perceives to be presenting an event, because it is an obstacle in its path or presents him a sudden danger; the first thing after a quick assessment of the circumstances, is to decide the maneuver that seems more convenient to circumvent the emergency.

Onibus no poste

To analyze the evolution of the accident, then they raised three (3) phases, namely:


At this stage all those involved in the accident (drivers or pedestrians), perceive a risk (Point of Perception Possible) and likewise the risk is understood as a danger (Point of Perception Real).

This moment of perception vary from those involved, because it can be influenced by special sensitivity motivated by, or practice reflections, producing a rapid response to stimulation, without an accurate perception of danger.

It is also important to know that for a driver traveling at a certain speed, angle Aplio present a vision always clear as it can perform movements of vision to the side. The higher the speed, the less (or no show) this movement is only a distant point and the clear visual angle is reduced in its 10 degrees is observed.


This second phase starts immediately after the sensing phase. It is people's reaction to the stimulus perceived imminent danger or accident.

In some cases this stage does not exist or does not occur, and therefore single phase perception of conflict or accident it occurs.

The reaction point is where the person is when he responds to the stimulus generated by the perception of danger and began a rapid assessment of the maneuver to be executed to avoid or minimize the damage caused by the accident.

During the short analysis that the person to select a maneuver, the reaction time, a certain time during which a driver has not executed the maneuver and the vehicle continues to move, a distance (reaction distance) is used . This is determined according to the time used to analyze and evaluate the danger and the speed at which the vehicle travels.

Then, this distance is added the distance traveled by the vehicle during the maneuver running the driver. If the selected maneuver was braking, the vehicle will require a minimum distance dependent on the rate at which the automobile travels.


It is where the accident occurs physically, despite making any evasive maneuver (braking or cornering). Although these Driving mechanism can reduce the severity of the accident, they were not sufficient, suitable or appropriate to prevent the accident.

A traffic accident investigator, a lawyer and a judge, has to be certain of the three phases mentioned here to proceed to determine the causes of the accident and the resulting responsibilities.

Photo credit: By Rodrigo César (Own work) [CC BY-SA 3.0 or GFDL], via Wikimedia Commons