law enforcement vehicle operations chapter 1

Centripetal force (tire traction)

is the force that is necessary to keep a vehicle moving in a curved path and is directed inward toward the center of rotation.

The caster effect

is the forward motion that causes a vehicle to straighten from a turn when releasing the steering wheel

Over steer

is the tendency of a vehicle to steer into a sharper turn than the driver intends, sometimes with a loss of traction of the rear to the outside.

Under steer

is the tendency of a vehicle to turn less sharply than the driver intends.

Yaw

is the transfer of a vehicle's weight causing an end-for-end motion resulting in the vehicle turning 180 degrees on a horizontal plane

A roadblock

is the use of vehicles, barricades, cones, or other objects to block traffic flow completely

The correction for over steer

is to remove the foot from the accelerator and/or brake, steer the car where desired (when the front tires have not lost traction), refrain from applying the brakes and if necessary, steer the car to a safe place and stop.

The center apexing technique

is when the vehicle is steered closest to the middle of the curve

The early apexing technique is

is when the vehicle is steered so it is closest to the inside of the curve before reaching the apex

Before using a vehicle,

its body must be inspected to identify any damage. An officer should conduct a quick visual examination of the vehicle's body and undercarriage and look for the following:

An incipient skid happens

just before the tires lose traction during braking. The tires lock, causing loss of steering control and a skid

according to the Florida case City of Pinellas Park v. Brown, 604 So.2d 1222 (Fla. 1990),

law enforcement has a duty to protect the public when choosing to continue a pursuit.

Driving in reverse requires

less steering input to produce a larger change in direction. Officers will find this especially evident when they drive the Reverse Serpentine course

Large or quick steering movements

may cause uncontrolled oscillation. Officers will find this evident when they drive the Tactical Backing course.

Driving to the right gives the other vehicle

more space and puts the officer in position to drive off the road if necessary

Pitch

occurs during acceleration or braking and causes the transfer of a vehicle's weight from front to rear or rear to front.

Roll

occurs when turning. This shifts the vehicle's weight from side to side

The psychological stress...

of an emergency call may cause you to exceed your ability or your vehicle's ability in trying to catch the offender at any cost or get there before anyone else.

Under poor road conditions or in inclement weather,....

officers should use the four-second rule. Its principles are the same as those of the two-second rule, except that four seconds are counted after the vehicle ahead passes a fixed object

Of particular concern on Florida roadways is ....

oil and tar.

Most law enforcement vehicles rest

on four, six-inch squares (known as the tire contact patch).

The trunk should be ...

opened and its contents inspected

PSI

(pounds per square inch)

There are three types of vehicular motion,

pitch, roll and yaw.

In Brower v. Inyo County, 489 U.S. 593 (1989), the U.S. Supreme Court addressed

the issue of deadly force in a police pursuit. In that case, the court held that certain pursuit tactics might result in a claim of a constitutional violation as a seizure by deadly force.

Embedded foreign objects

can deflate or blow out a tire. However, an officer should not pull out the object but allow the dealer or maintenance personnel to handle the removal

The two general forces that act upon a vehicle as it turns a corner are

centripetal force and centrifugal force.

While driving, officers may encounter

concrete (a nonporous supportive surface), asphalt (a porous distributive surface), clay, dirt, gravel, or brick roadways.

Hoses should be checked for

dry rot, cracking, holes, bulges, and leaks

Officers are likely to encounter potential hazards

due to road and weather conditions

Physiological effects are

the measurable changes to normal body functions. These include tunnel vision, selective hearing, increased heart rate, time distortion, and loss of spatial awareness or fine motor skills.

Officers should be especially careful at intersections, as they represent

the single greatest threat to safe vehicle operation.

If the rear tire fails

the vehicle may also lose traction and pull in an unpredictable direction.

After police restrict the person's freedom of movement,

they assume responsibility for that person's safety and must keep the person reasonably free from harm

An officer should always offset his or her vehicle .....

to the left of the available roadway but within his or her lane. That makes the vehicle more visible to the vehicles the officer is following as well as those approaching from the opposite direction

Tires should be checked for

uneven wear that may result from improper balance or alignment, over inflation, or under inflation.

The following steps explain the proper technique for accelerating a vehicle while avoiding loss of traction and controlling weight transfer

6. Release the pressure on the pedal as needed to control loss of traction or decrease the acceleration rate.

A radius

A radius is the distance from the center of a circle to the outside of the circle.

loss of visual cues:

At night, it is easy to lose many visual cues that are available during the day, which lowers the ability to judge distance and the speed of oncoming traffic.

field of vision:

At night, peripheral vision decreases. Less light narrows the field of vision.

these are essential for the safe operation of the vehicle and should be inspected each day

Belts, hoses, and wires

glare:

Glare from oncoming vehicles or other outside sources can temporarily blind a driver.

The late apexing technique

It allows the most room for driver error

Shuffle Steering

It is imperative to use this steering technique because it helps maintain control of the steering wheel, especially when the caster effect occurs.

must be stored across the width of the trunk (side-to-side, not front to back).

Long and protruding equipment (i.e., long guns, long-handled tools, and equipment. This will eliminate protrusion into the passenger compartments or the gas tank in the event of a rear-end collision.

overdriving of vehicle headlights

The most common night driving error is to overdrive the distance the vehicle's headlights project. According to F.S. s. 316.237, vehicle headlights should reveal a person 450 feet away with the high beams and a distance of 150 feet with the low beams.

Immobilization Technique (PIT)

The purpose of this technique is to stop a violator's vehicle by using the police vehicle to apply force to either the rear right or left side of the violator's vehicle to end the pursuit.

Some temporary factors can weaken a driver's observation skills

These include stress, emotions, fatigue, and frequent shift changes. Prescription and over-the-counter drugs and poor driving habits can also have an effect on an officer's observational levels, resulting in inattention, loss of control, and even crashes.

Recovering from a Slide

Use counter steering; turn the vehicle's front tires in the direction you want to go.

In the Pinellas Park case, officers and deputies from three different jurisdictions engaged......

approximately 15 police cars in a pursuit on the main roadway.

Vision supplies

approximately 90-95 percent of incoming data to a driver. It gives valuable information needed to detect and avoid hazards

Responding in emergency mode or pursuing a vehicle

are among the most dangerous driving situations because the officer may experience psychological and physiological effects.

The two-second rule establishes

a minimum safe following distance for all vehicles and provides space and time for the driver to react to potential hazards

Hearing lets officers locate the source of sounds that may indicate

a problem with a vehicle, a suspicious incident, or a crime.

trunk Inside should be

a spare tire, vehicle jack, tire tool, and assorted equipment for use on duty (usually issued by the agency).

depth perception

ability to judge distance and perceive space to determine how far away an object is •

peripheral vision

ability to see above, below, and to the sides (A person who is in a stationary vehicle and who has good peripheral vision can see about 180 degrees from side to side.)

for personal safety,

an officer should perform inspections before and after every use of the vehicle

Cornering requires

entering an intersection safely and properly at normal driving speeds and making a 90-degree turn to the right or left.

In addition, wires should be checked for

fraying, corrosion, cracked or missing insulation, and exposure

Belts should be checked for

fraying, cuts, cracking, and gouges

These provisions do not relieve the law enforcement driver of a vehicle specified in paragraph F.S. s. 316.072(5)(a)1 and 4(c)

from the duty to drive with due regard for safety of all persons, nor do they protect the driver from the consequences of his or her reckless disregard for the safety of others.

Driving with the window down also

helps alert the officer to other emergency vehicles (fire trucks, rescue vehicles, and police or other emergency vehicles responding to the same scene).

If the officer cannot avoid hitting a fixed object or an oncoming vehicle, the officer should

hit the object with the side of the vehicle rather than head on, glancing off the object or vehicle.

Though they are designed to disperse water, tires sometimes

hydroplane.

Other factors that may effect the ability to operate and control a vehicle are

including vehicle speed and glare from the sun or other lighting sources, may also influence an officer's observation skills

A decreasing radius

is a turn that gets tighter during the turn much like a circle getting smaller

An increasing radius

is a turn that gets wider during the turn much like a circle getting larger

A constant radius

is a turn that remains the same throughout, getting neither wider nor smaller.

Pursuit

is an active attempt by an officer, driving an authorized emergency vehicle (with emergency equipment activated), to apprehend occupants of a moving vehicle if the offender increases vehicle speed, takes other evasive actions, or refuses to stop in an apparent attempt to avoid apprehension.

Wheel tracking

is an occurrence that causes the rear wheels to follow a tighter path than the path the front wheels traveled in a turn

Enhancement to the conventional braking system called anti-lock braking system (ABS) .

is now standard equipment on late model vehicles.

An apex

is the center point of any curve.

Centrifugal force

is the force enacted on a vehicle moving in a curved path that acts outwardly away from the center of rotation.

The correction for under steer is to...

remove the foot from the accelerator, maintain steering input but do not apply brakes, and if necessary, steer the car to a safe place and stop.

A slide also

results from loss of both rolling friction and traction

acuity

sharpness of vision

As a vehicle's tracking width decreases,

so does its stability. Trucks and SUVs are less stable because of their narrow tracking width.

In DeShaney v. Winnebago County Department of Social Services, 489 U.S.189 (1989), the U.S. Supreme Court

stated that an officer or agency has no duty to guarantee a person's safety unless a special relationship exists between the police and that person

When an officer cannot avoid striking or driving over obstacles, the officer should

strike it at a slight angle (when possible) with free rolling tires. If two or more vehicle tires roll from a paved surface onto an unpaved surface, the officer should not attempt to return to the paved surface by abruptly turning the steering wheel. This can cause the vehicle to flip or cross several traffic lanes. Instead, the officer should decelerate and steer as straight as distance allows.

Several factors can make the source of a sound difficult to find

such as whether the driver's windows are open or closed, if there are surrounding buildings, etc

The late apexing

technique is when the vehicle is steered so it passes closest to the inside of the curve after reaching the apex

The recommended PSI can be found on

the doorjamb

With proper braking technique,

the driver presses the brake pedal with increasing pressure, to slow or stop as quickly as possible

According to F.S. s. 316.271(6),

very authorized emergency vehicle shall be equipped with a siren, whistle, or bell capable of emitting sound audible under normal conditions from a distance of not less than 500 feet and of a type approved by the department, but such siren, whistle, or bell shall not be used except when the vehicle is operated in response to an emergency call or in the immediate pursuit of an actual or suspected violator of the law, in which event the driver of the vehicle shall sound the siren, whistle, or bell when reasonably necessary to warn pedestrians and other drivers of the approach thereof

A skid results

when the wheels lock and do not turn while the vehicle is moving

Because Florida officers are bound by the Pinellas Park v. Brown decision

which imposed a negligence standard for injuries caused during chases, the Scott decision does not give the green light for an "anything goes" approach to pursuits.

The best traction is rolling friction

which is when the tires constantly rotate on the road surface without losing contact

tips officers should follow to prevent accidents

• Assume other drivers will make errors

Officers must demonstrate effective cornering by making right and left turns following these steps:

• To ensure steady weight transfer, maintain a constant speed while entering the turn

Several components of vision may affect the ability to operate and control a vehicle:

• acuity • depth perception • peripheral vision

The fluid levels to be checked include the following:

• engine oil (measured in quarts) • brake fluid • coolant reservoir • transmission fluid (measured in pints) • power steering fluid • windshield washer fluid

There are techniques officers can use to improve their vision while driving at night and react properly to oncoming vehicular traffic. These techniques include the following:

• looking off to the shoulder of the roadway to protect night vision while using the white line at the edge of the road for guidance

look for the following when inspecting the outside and inside of vehicle

• scratched paint that may be the result of contact with an object or intentional damage • dents that are more obvious signs of contact with another object, perhaps a vehicle • missing or broken light covers that can present a hazard to other drivers and may be a traffic violation • a dirty windshield that could impair observation ability

Some frequently occurring crashes include the following

• side swipes