Police Vehicle Operations and Accident Susceptibility

Vocabulary terms and definitions regarding the factors surrounding police motor vehicle accidents, defensive driving components, stopping distance metrics, and safety protocols.

Unit Goal P.O. 7.1

To identify the factors that make an officer susceptible to vehicle accidents.

Traffic Collision Experience Ratio

The experience among law enforcement drivers is almost $3$ times greater than that of non-law enforcement drivers.

Crash Expectancy Rate

Based on national averages, a law enforcement officer can expect to be involved in a crash every $28,000$ miles of driving.

Traffic-Related Fatality Percentage

Approximately $52\%$ of police officer fatalities are traffic related.

Common Driver Response to Emergency

The most common response to an emergency situation is to slam on the brakes.

Preoccupation (Inattentiveness)

A response to boredom, monotony, or stress that is the source of most law enforcement motor vehicle injuries.

Peak Fatigue Time

Officers typically report experiencing the most fatigue during the last $45$ minutes of a shift.

Marked Police Vehicle Syndrome

The phenomenon where civilian drivers react to seeing a marked vehicle and the officer falls into the trap of believing everyone will get out of the way.

Components of Defensive Driving

Four specific factors: Driver Attitude, Driver Skill, Vehicle Capability, and Driving Conditions.

Perception Time

The time it takes to recognize a hazard exists, which averages approximately $\frac{3}{4}$ of a second.

Reaction Time

The time it takes to begin braking once a hazard is perceived, which averages approximately $\frac{3}{4}$ of a second.

Minimum Daytime Perception/Reaction Time

A baseline duration of $1.6$ seconds used for daytime distance calculations.

Minimum Nighttime Perception/Reaction Time

A baseline duration of $2.6$ seconds used for nighttime distance calculations.

Perception/Reaction Distance

The distance covered, measured in feet, during the time information is sent to the brain and an action begins.

Braking Distance

The distance the vehicle travels once the brake is actually applied.

Total Stopping Distance

The sum of the perception/reaction distance plus the braking distance.

Momentum

A tendency of any object in motion to remain in motion.

Intersection Accident Cause

Approximately half of intersection accidents involve emergency vehicle drivers ignoring a traffic control device.

L-R-L Sequence

A left-right-left visual check sequence used to negotiate intersections after waiting $1-2$ seconds on a green light.

Passing Rule for Emergency Driving

A technique stating that an emergency driver should never pass on the right.

Proper Backing Technique

Keep the right arm up over the seat, lift self up, and look directly over the right shoulder out of the back window.

Siren Audibility Obstruction

A siren may not be audible if the windows are up and the radio or air conditioner is on.

Radio Transmission Safety

Officers should transmit while driving in a straight line and never steer with the radio mica in their hand.