Vehicle Operations

Vision Types

• Acuity refers to the sharpness of vision.

Depth Perception

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

Peripheral Vision

• The ability to see above, below, and to the sides.
• A person with good peripheral vision can see about 180º from side to side, especially when stationary, such as in a vehicle.

Color Vision

• The ability to distinguish colors.

Night Vision

• The ability to see clearly in darkness.

Types of Vehicular Motion

• There are three types of vehicular motion: pitch, roll, and yaw.

Pitch

• Occurs during acceleration or braking.
• Causes the transfer of a vehicle's weight from front to rear or rear to front.

Roll

• Occurs when turning.
• Shifts the vehicle's weight from side to side.

Yaw

• Causes an end-for-end motion resulting in the vehicle turning 180° on a horizontal plane.
• Involves the transfer of a vehicle's weight.

Vehicular Stability

• Vehicular stability affects the degree of pitch, roll, and yaw that a vehicle experiences
• A stable vehicle is more resistant to pitch and roll compared to an unstable vehicle

Factors Affecting Stability

• The center of gravity on the most stable vehicle is low and centered
• A higher center of gravity results in lower stability
• Vehicles with a wider tracking width are more stable
• Vehicles with a narrower tracking width are less stable

Examples of Vehicle Stability

• Formula One or Indy race cars are examples of stable vehicles with a low and centered center of gravity
• Trucks and SUVs are less stable due to their high center of gravity and narrow tracking width
• Military Humvees are more stable due to their wider tracking width

Electronic Stability Control (ESC)

• ESC helps drivers maintain control of their vehicle during extreme steering maneuvers
• ESC prevents loss of control when the vehicle nears or exceeds the limits of road traction

Traction Control System (TCS)

• TCS is typically a secondary function of ESC
• TCS prevents loss of traction

Weight Transfer and Distribution

• Weight transfer occurs when the vehicle's speed changes, affecting its handling ability.
• Weight is distributed only where the tires contact the surface.

Effects of Braking and Acceleration

• Applying the brakes causes weight transfer in the direction of travel, affecting the stopping distance.
• Weight transfer is more dramatic when brakes or accelerator are applied more dramatically.
• Accelerating transfers weight to the rear tires, affecting acceleration and handling.

Effects of Turning and Cornering

• Weight is transferred from one side to the other when a vehicle turns a corner.
• Weight transfer is more noticeable in vans, trucks, or SUVs than in sedans.
• Weight transfer can force the vehicle out of its travel lane or off the road in extreme situations.
• In extreme cases, it can cause the vehicle to roll over.

Vehicle Dynamics

• When a driver applies the brakes, weight transfers forward or backward in the direction the vehicle is traveling.
• This weight transfer affects the distance it takes to stop the vehicle.
• When a vehicle accelerates, weight transfers to the rear tires, affecting both acceleration and vehicle handling.

Weight Transfer During Turns

• When a vehicle turns a corner, weight transfers toward the tires on the outside of the turn.
• The front outside wheel carries the most weight during a turn.
• The rear wheel on the outside of the turn carries less weight than the front outside wheel.
• The front wheel on the inside of the turn carries even less weight than the rear wheel on the outside.
• The rear wheel on the inside of the turn carries the least weight.

Safe Driving Practices

• Avoid braking and steering at the same time to maintain control and avoid accidents.
• Always brake before turning to ensure stable weight distribution and optimal traction.
• After braking, steer into the turn to maintain control and avoid losing traction.

Circle and Turn Basics

• A radius is the distance from the center of a circle to the outside.
• A turn or curve is a portion of a circle.

Types of Turns

• An increasing radius is a turn that gets wider during the turn, similar to a circle getting larger.
• A decreasing radius is a turn that gets tighter during the turn, similar to a circle getting smaller.
• A constant radius is a turn that remains the same throughout, getting neither wider nor smaller.

Safe Turn Negotiation

• Safely negotiating a tight turn requires less speed and more steering input.

Types of Turns

• An increasing radius turn is a turn that gets wider during the turn, similar to a circle expanding in size.
• A constant radius turn is a turn that maintains the same width throughout, without getting wider or smaller.

Safe Turning Techniques

• Safely negotiating a tight turn requires reducing speed and increasing steering input.

Apexing Techniques

• The apex is the center point of any curve.
• Apexing technique refers to how a vehicle is steered in relation to a curve's apex while maintaining its lane.

Types of Apexing Techniques

• Early Apexing: Steering the vehicle closest to the inside of the curve before reaching the apex.
  • Increases the force enacted on a vehicle moving in a curved path.
  • Moves the vehicle outward, away from the center of the curve.
  • Can cause loss of control.
• Center Apexing: Steering the vehicle closest to the middle of the curve.
• Late Apexing: Steering the vehicle closest to the inside of the curve after reaching the apex.
  • Decreases the force enacted on a vehicle moving in a curved path.
  • Reduces the potential for loss of control.
  • Generally considered the best cornering or turning method.
  • Allows the most room for driver error.

Vehicle Handling

• Understeer: tendency of a vehicle to turn less sharply than intended due to excessive speed, lack of traction on steering tires, and improper braking in a turn or curve.
• Correction for understeer: remove foot from accelerator, maintain steering input, don't apply brakes, and steer to a safe place if necessary.

Oversteer

• Tendency of a vehicle to steer into a sharper turn than intended, potentially losing traction on rear tires.
• Occurs at higher speeds with excessive braking in a turn or curve.
• Correction for oversteer: remove foot from accelerator and/or brake, steer to desired direction, refrain from applying brakes, and steer to a safe place if necessary.

Wheel Tracking

• Phenomenon where rear wheels follow a tighter path than the front wheels in a turn.
• When avoiding a fixed object, steer the front of the vehicle wide to prevent rear wheels from striking it.

General Handling

• Applying correct inputs makes a driver more capable in both normal and extreme conditions.

Officers' Duty to Care

• Court cases examine the responsibility of law enforcement officers to ensure public safety while operating vehicles.
• The U.S. Supreme Court ruled in DeShaney v. Winnebago County Department of Social Services (1989) that officers have no duty to guarantee a person's safety unless a special relationship exists.
• A special relationship is established when law enforcement restricts a person's freedom of movement, such as when they take someone into custody.
• In such cases, law enforcement assumes responsibility for the person's safety and must ensure they are reasonably free from harm.

Law Enforcement Duty to Protect the Public

• In the City of Pinellas Park v. Brown case (1992), the Florida Supreme Court ruled that law enforcement has a duty to protect the public when deciding to continue a pursuit.

The Pinellas Park Case

• Multiple law enforcement agencies pursued a vehicle with 15 law enforcement vehicles on a main roadway.
• Officers and deputies from three jurisdictions violated department policies by continuing the pursuit.
• An unmarked law enforcement vehicle entered the roadway, causing two sisters waiting to cross the road to be unaware of the approaching pursuit.
• The sisters pulled into the path of the pursued vehicle, resulting in a fatal accident that killed the sisters and the fleeing driver.

Key Takeaways from the Court's Ruling

• The Florida Supreme Court held that law enforcement's actions created a foreseeable and preventable risk to the public.
• The court did not prohibit law enforcement pursuits, but stated that such decisions are subject to court review under the doctrine of negligence, not just as a use of force under the Fourth Amendment.
• Law enforcement has a duty of care to residents, and if their actions or inactions cause injury or death, the court must determine whether they acted reasonably.

Modern Policing and Pursuits

• "Losing" a vehicle during a pursuit does not mean law enforcement will never find the vehicle or bring its occupants to justice.
• It is not always a matter of "catching them now or never."
• Following agency policies is the best way to avoid liability in a pursuit scenario.

Vehicle Handling and Control

• When a vehicle turns a corner, weight transfers toward the tires on the outside of the turn.
• The front outside wheel carries the most weight, while the rear wheel on the outside of the turn carries less.
• Weight transfer affects the vehicle's handling and braking capabilities.

Radius and Turn Types

• A radius is the distance from the center of a circle to the outside.
• A turn or curve is a portion of a circle.
• There are three types of turn radii: increasing, decreasing, and constant.
• An increasing radius is a turn that gets wider during the turn.
• A decreasing radius is a turn that gets tighter during the turn.
• A constant radius is a turn that remains the same throughout.

Apexing Technique

• The apex is the center point of any curve.
• The apexing technique refers to how the vehicle is steered in relation to a curve's apex while maintaining the lane.
• There are three types of apexing techniques: early, center, and late.
• Early apexing can cause loss of control due to increased force on the vehicle.
• Late apexing is the best cornering or turning method, as it allows for the most room for driver error.

Vision and Perception

• Acuity refers to sharpness of vision.
• Depth perception is the ability to judge distance and perceive space.
• Peripheral vision is the ability to see above, below, and to the sides.
• Color vision is the ability to distinguish colors.
• Night vision is the ability to see clearly in darkness.

Vehicular Motion

• There are three types of vehicular motion: pitch, roll, and yaw.
• Pitch occurs during acceleration or braking and causes weight transfer from front to rear or rear to front.
• Roll occurs when turning and causes weight transfer from side to side.
• Yaw is the transfer of weight causing an end-for-end motion, resulting in the vehicle turning 180° on a horizontal plane.

Vehicle Stability and Control

• Vehicular stability affects the degree of pitch, roll, and yaw.
• A stable vehicle has a low and centered center of gravity, such as a Formula One or Indy race car.
• A higher center of gravity results in lower stability.
• Electronic Stability Control (ESC) helps drivers maintain control during extreme steering maneuvers.
• Weight transfer and distribution occur when the vehicle's speed changes, affecting its handling ability.

Understeer and Oversteer

• Understeer is the tendency of a vehicle to turn less sharply than intended.

• Causes of understeer include excessive speed, lack of traction, and improper braking in a turn or curve.

• The correction for understeer is to remove the foot from the accelerator, maintain steering input, and steer to a safe place and stop.

• Oversteer is the tendency of a vehicle to steer into a sharper turn than intended.

• Causes of oversteer include higher speeds, loss of traction, and excessive braking in a turn or curve.

• The correction for oversteer is to remove the foot from the accelerator and/or brake, steer the car to a safe place, and stop.

Court Cases and Law Enforcement

• Court cases address officers' duty to care for the public while operating law enforcement vehicles.
• In DeShaney v. Winnebago County Department of Social Services, 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.
• In City of Pinellas Park v. Brown, the Florida Supreme Court held that law enforcement has a duty to protect the public when choosing to continue a pursuit.
• Law enforcement action or inaction that causes injury or death to a person is subject to court review under the doctrine of negligence.

Brower v. County of Inyo (1989)

• The US Supreme Court addressed the issue of deadly force in law enforcement pursuit
• The Court held that certain pursuit tactics might result in a claim of a constitutional violation as a seizure by deadly force
• In the Brower case, law enforcement set up a roadblock by parking an 18-wheeler around a curve in the roadway
• A law enforcement vehicle was placed with its headlights positioned to blind Brower as he drove around the curve
• The combination of the roadblock and blinding headlights caused Brower to strike the stationary truck, resulting in his death

Vehicle Dynamics and Handling

• When a vehicle turns a corner, weight transfers toward the tires on the outside of the turn, with the front outside wheel carrying the most weight.
• The correct braking and steering technique is to brake before turning and then steer into the turn.

Turn Radius and Apexing

• A radius is the distance from the center of a circle to the outside.
• There are three types of turns: increasing radius (turns that get wider), decreasing radius (turns that get tighter), and constant radius (turns that remain the same).
• Apexing technique is how a vehicle is steered in relation to a curve's apex while maintaining the lane.
• There are three apexing techniques: early (steering closest to the inside of the curve before reaching the apex), center (steering closest to the middle of the curve), and late (steering closest to the inside of the curve after reaching the apex).

Visual Perception and Vehicular Motion

• Visual perception is critical for safe driving, including acuity (sharpness of vision), depth perception, peripheral vision, color vision, and night vision.
• There are three types of vehicular motion: pitch (forward and backward weight transfer), roll (side-to-side weight transfer), and yaw (end-for-end motion).
• Vehicular stability is affected by the center of gravity (lower and centered for more stability) and tracking width (wider for more stability).

Electronic Stability Control and Weight Transfer

• Electronic Stability Control (ESC) helps drivers maintain control during extreme steering maneuvers.
• Traction control system (TCS) is a secondary function of ESC that prevents loss of traction.
• Weight transfer and distribution occur when a vehicle's speed changes, affecting handling ability.
• Weight transfer occurs when braking (forward or backward) or accelerating (rearward).

Understeer and Oversteer

• Understeer is when a vehicle turns less sharply than intended, often due to excessive speed, lack of traction, or improper braking in a turn.
• Correction for understeer is to remove foot from the accelerator, maintain steering input, and steer to a safe place.
• Oversteer is when a vehicle steers into a sharper turn than intended, often due to loss of traction of the rear tires, especially at higher speeds.
• Correction for oversteer is to remove foot from the accelerator and/or brake, steer the car to a desired path, and refrain from applying brakes.

Police Pursuits and Liability

• Law enforcement has a duty to care for the public while operating vehicles, with a special relationship existing between law enforcement and individuals in custody.
• The Florida case City of Pinellas Park v. Brown (1992) held that law enforcement has a duty to protect the public when choosing to continue a pursuit.
• The U.S. Supreme Court case DeShaney v. Winnebago County Department of Social Services (1989) stated that an officer or agency has no duty to guarantee a person's safety unless a special relationship exists.

Supreme Court Decision

• The Court's opinion was heavily influenced by the Tennessee v. Garner decision (471 U.S. 1, 1985)
• The Court focused on the use of deadly force to apprehend a person for a non-dangerous crime
• A distinction was made between pursuing and blocking or seizing a person

Seizure and Police Responsibility

• Brower was considered seized, as law enforcement actively tried to block him
• The responsibilities associated with seizure applied to the police actions in this case

Brower v. County of Inyo (1989)

• The US Supreme Court addressed the issue of deadly force in law enforcement pursuit.
• The Court held that certain pursuit tactics might result in a claim of a constitutional violation as a seizure by deadly force.

Facts of the Case

• Law enforcement set up a roadblock by parking an 18-wheeler around a curve in the roadway.
• They placed a law enforcement vehicle with its headlights positioned to blind Brower as he drove around the curve.
• The combination of these actions caused Brower to strike the stationary truck, resulting in his death.

Court's Opinion

• The Court relied heavily on its earlier decision in Tennessee v. Garner (1985) regarding deadly force.
• The Court was concerned with the use of deadly force to apprehend a person for committing a non-dangerous crime.
• The Court drew a distinction between the act of pursuing and the act of blocking or seizing a person.

Key Takeaways

• Brower was clearly seized, and law enforcement actively tried to block him, so responsibilities associated with seizure applied to their actions.
• The Court took the position that deadly force should not be used to apprehend citizens for minor offenses such as traffic violations.
• The distinction between pursuing and seizing highlights the relationship between the violator's and officers' actions.
• When merely pursuing, officers have no special relationship with the violator and assume no responsibility for the violator's injury or death.
• If officers take affirmative steps to halt or force the fleeing individual to stop, they are responsible for the results, and their actions become a seizure under the Fourth Amendment.

Liability for Injury or Death Caused by Pursuit or Emergency Response

• The standard for judging officer liability for injury or death caused by pursuit or emergency response was established in County of Sacramento v. Lewis (1998).
• The "shock the conscience" standard is used to determine liability, which is decided on a case-by-case basis.
• The standard distinguishes between mere carelessness or negligence, deliberate indifference, and the intent to cause harm.
• To meet the "shock the conscience" standard, an officer must have intended to cause harm to the violator without justification for the use of deadly force during a high-speed pursuit.

Scott v. Harris (2007)

• US Supreme Court decided a pursuit/use of force case in 2007
• Involved Deputy Scott pursuing Victor Harris for a traffic offense at high speeds
• Scott attempted to terminate the chase using PIT (Pursuit Intervention Technique) at a higher speed than recommended by training

Key Ruling

• Justice Scalia wrote that the only consideration is whether Scott's actions were reasonable
• Disagreed with Harris' argument that public could have been protected by stopping the chase

Effect of the Ruling

• Does not condone an "anything goes" approach to pursuits due to Florida's negligence standard for injuries caused during chases (Pinellas Park v. Brown)
• Under the Fourth Amendment's use of force analysis, injury to the fleeing driver will generally not be considered the result of unreasonable force