Presentation on theme: "Virginia Driver Education"— Presentation transcript:
1Virginia Driver Education Module ThreeVision, Vehicle Balance and Laws of Nature
2With a PartnerDiscuss and write down all the pre-driving checks that you should perform once you are in your vehicle (assume you are already buckled in).Next, discuss and write down all the steps to take as you exit your vehicle.
3Topic 1 - Starting Tasks Check/set park brake (P) and place Right foot on brake pedal, heel on floorLeft foot on “dead pedal” for balanceKey in ignition, and turn toward startCheck alert, warning lights and gaugesAdjust ventilation, accessories, etcTurn headlights on
4Securing the Vehicle Find a LEGAL, safe parking place Stop and set parking brakeShift gear selector to (P)ark (Shift to Reverse if Manual Transmission)Close windowsTurn off accessoriesTurn ignition switch to “off”Lock ignition switch and remove keyUnfasten occupant restraints
5Exiting the Vehicle Check traffic flow to rear prior to opening door Monitor door swing into adjacent lane or when parked next to another vehicleExit quickly to avoid conflict with trafficLock doorsWalk toward rear of the vehicle facing traffic
6Topic 2 - Vision and Driving Drivers base about 90% of all driving decisions on what they see, and % on what they hear or feelDrivers must be able to look far enough ahead to make good decisions about speed, lane position, signs, signals, markings, and potential hazardsDrivers must be able to see near and far--close enough to read the speedometer, and far enough ahead to see/adjust for hazards
7With a Partner... Discuss and write down: Anything that can blur your vision when driving.What can you do to enhance your vision when driving?Where should you be looking when you are driving?
8Effective Use of Visual Fields The Three Visual FieldsFovea VisionVisual Lead, Targeting, Signs, SignalsCentralReferencing, Path of TravelPeripheral VisionMotion and Color Changes
9The Fovea Vision AreaLocated at the center of the central vision area, the fovea is a small part of the retina and is responsible for our highest visual acuity
10Central Vision An area 35 to 38 degrees around foveal vision used for: Central Vision Area (Inner Fringe)An area 35 to 38 degrees around foveal vision used for:Referencing Vehicle Position to RoadwayViewing Path of Travel
11Central Vision at Night The human eye’s field of vision is much smaller without the help of natural lightDepth perception, visual acuity, and color recognition are all compromised at nightMinimize glare by looking at the bottom right of the road to avoid approaching headlightsKeep it dark in the carSlow down to give yourself longer to react
12Approximately 90 degrees of vision to each side Peripheral VisionApproximately 90 degrees of vision to each sideIncreases total field of vision to about and is used to see:Objects to the sideMovement and color changes to the side
13Peripheral Vision and the Driving Task Drivers use peripheral vision to:See color and object movementSee signal changes, road signs, warning lights on the dashboardMonitor trafficStay within the lane
14Night Time Peripheral Vision Is reduced dramatically due to lack of light to retina and glareWhile Foveal and Central Vision are also reduced, they become more critical for searching for problems
15With a partner:What would you see using Fovea, Central, and Peripheral Vision?
16Vision is Affected by: Smoke Speed Age Fatigue Dirty Windshield Drugs Poor Windshield WipersPoor night visionNight BlindnessSpeedFatigueDrugsPoor weatherDarknessGlareInattention
17Depth PerceptionNeed both eyes to judge the distance between two objectsDepth perception allows you to:judge gaps in traffic when turning, merging, or passingjudge distance when approaching a vehicle or obstruction
18Poor Depth Perception Stop too far from the stop line or intersection Stop too close to vehicles aheadMove into gaps that are too smallLook for gaps that are larger than needed to perform a maneuverFollow other vehicles at unsafe following distanceHit parked cars when parkingHave “close calls” when entering traffic, passing, etc.
19As speed increases Central vision decreases and blurs Peripheral vision decreasesChanges in steering exaggerate vehicle movementMOST IMPORTANTLY:VISION FIELDS NARROW
20Ways to Improve the Vision Fields Clean windows—inside and outClean lights—be sure they workCheck defroster and wiper bladesRemove any objects that interfere with visionAdjust mirrors properlyKeep sunglasses, flashlight, windshield scraper in vehicle
21Line-of-sight is the distance you can see in your path of travel
22Line-of-Sight (LOS) Restrictions Vision is blocked, speed and position adjustments may be needed until LOS is restored
23The space the vehicle will occupy while traveling to the target area Path-of-Travel (POT)The space the vehicle will occupy while traveling to the target area
24Examples of Path-of-Travel Restrictions Space is not available for the vehicleNarrow lane and no shoulderVehicle stopped or blocking intersection
25“Target” Far Ahead in the Path of Travel Identify the target in this driver’s path of travelA “Target” is an object or place far ahead in the center of your path of travel
26Target AREA Provides the BIG Picture The Target area is the area drivers must scan to the left and right of the targetTarget Area
27The Pavement Around Your Vehicle You Cannot See From the Driver’s Seat The driver cannot see anything on the ground in the area outlined above—cars are used to show the size of this area
28Determining Driver Blind Areas Marker (foot or cone)To do this:Have someone stand outside of the car and continue to back up until you can see their feet.You will be surprised at how far they have to go!
29Using Lane Position to Maximize LOS 1Select the lane position that gives you the best line of sight and safest path of travelLane positions are based upon an average lane size of 12-feet wide, and a vehicle 6-feet wide2345
30Lane Position 1 2-3 Feet 2-3 Feet Positioned in the center of lane with an equal buffer of space on either side
31Lane Position 23-6 InchesAllows for 6 feet of space to the right of the vehicle. Used to prepare for a left turn or when avoiding a problem to the right of the vehicle.
32Lane Position 33-6 InchesAllows for 6 feet of space to the left of the vehicle. Used to prepare for a right turn or when avoiding a problem to the left of the vehicle.
33Lane Positions 4 and 545Lane positions 4 and 5 – straddling the line to avoid a problem within a lane
34Topic 3 - Basic Maneuvers -- Steering Holding the upper half of the wheel can result in excessive steering, air bag injuries, and upper body fatigueHands located on lower half of thewheel offers:Relaxed, balanced controlReduces unwanted steering wheel movementImproves stability by lowering the body’s center of gravity
35Hand-to-Hand/Push-Pull Steering Hand-to-Hand Steering/Push-Pull Right TurnLeft Hand Pushes Up from 8 to 11Right TurnRight Hand Pulls Down from 1 to 4
36Hand-Over-Hand Steering Used at Speeds below 15 mph Used for slow, tight turns - Arms cross on the top 1/3 of the wheel until desired path of travel is reachedLeft Turn/left handLeft hand pulls down, then reaches up to about theo’clock position and continues to pull down to the leftLeft Turn/right handRight Hand pushes up to about the 11 o’clock position
37One-Hand Steering Is used when: Backing straight--hand holds top of wheel.Backing a trailer--hand holds bottom of wheel.Backing Position
38Covering the Accelerator Used for a smooth transition from braking to acceleratingAllows the vehicle to coast which may speed up or slow down the vehiclePermits the driver to be prepared for any needed acceleration
39Acceleration Techniques Progressive, Smooth AccelerationHeel pivots foot from the brake to the acceleratorGently apply pressure to the accelerator pedal to gradually increase speed to minimize backward pitch and maintain vehicle balanceHow do you know if you are and smoothly gaining speed?
40Acceleration Techniques (cont) 2. Thrust AccelerationTypically used when passing or merging into higher speed trafficGreater pressure is applied to accelerator pedal to rapidly increase speed without losing tire traction
41Braking Techniques Smooth braking technique: Is a trait of a skilled driverSaves wear and tear on the brake system and tires
42Methods to Reduce Speed Release the AcceleratorMost frequently used method to slow vehicle speedGradually reduce pedal pressure to avoid abrupt changes in speed
43Methods to Reduce Speed 2. Controlled Braking - When releasing the accelerator is not enoughCheck the rear view mirrorRelease accelerator and apply smooth, steady pressure on the brake pedalFor a smooth STOP, gently ease off the brake a few seconds before stopping to reduce the vehicle’s weight shift so the car does not pitch forward then backward during the final phase of stopping
44Methods to Reduce Speed (cont) 3. Threshold Braking in an EmergencySlows the vehicle as quickly as possible without locking brakes or losing tractionRelease accelerator while checking traffic behindExert forceful pressure on brake pedal and you will feel the vehicle weight shift forwardIf you feel the wheels begin to slide, ease the pressure on brake pedal so the tires can begin rotating again
45Methods to Reduce Speed (cont.) 4. Trail Braking – Used for Sharp TurnsOccurs at the transition point where you slightly reduce pressure on the brake pedal to allow the vehicle to begin to regain speed before applying the accelerator
46Trail Braking 1. Use controlled braking prior to reaching the curve 2. Begin easing off brake, and trail brake with very light pressure until halfway through the turn,3. Accelerate out of the turn
47Anti-Lock Braking System (ABS) ABS allows maximum stopping force without locking up the brakes (skidding) If standard brakes are applied too hard, the wheels "lock" or skid, and you lose steering control.
48Anti-Lock Braking System (cont) If steering control is lost, the vehicle skids in a straight line wherever it is goingABS is an anti-lock/anti-skid brake system that allows the driver to steer during hard braking
49Anti-Lock Braking System (cont.) The ABS warning will come on when there is a problem with either the ABS brake system, normal brake system, or the brake fluid is low in the master cylinder or the ABS brake systemTo find out if a vehicle is equipped with ABS, turn on the ignition and check the instrument panel for the ABS indicator light
50Myths about ABSThere are fewer fatal crashes for cars equipped with ABSFalse, some drivers panic and/or release the brake when it pulsesDon’t use ABS brakes on a slippery surfaceFalse, ABS shortens stopping distance and improves control on a slippery roads
51Has there ever been a situation when you or a parent had to use threshold braking?
52Maintaining Vehicle Balance Vehicle balance is the distribution of the weight of the vehicle on the tiresOptimum balance is reached when the vehicle is not moving or is moving in a straight direction at a constant speedAs soon as the vehicle accelerates, brakes, or turns, the balance is changed and the weight transfer changes the size of the tire patches
53Inertia Inertia wants to keep these parked vehicles at rest Inertia also wants to keep these moving vehicles moving
54Inertia (cont.)When driving through this curve, inertia creates the sensation that you are being pulled toward the outside of the curveWhy?Because you are traveling in a straight line, and inertia wants to keep you going in a straight line
55Momentum = Mass x Velocity Momentum is inertia in motionMomentum is the product of speed and weightAs momentum increases so does the potential for damage in a collision
56With a Partner Where does weight shift when you accelerate? When you decelerate?What about when you are approaching a right turn? Left turn?
57Pitch, Roll, and YawPitch, Roll, and Yaw are the three axes running through a vehicle’s center of gravityYawPitchRoll
58Vehicle’s weight shifts backward or forward Vehicle PitchVehicle’s weight shifts backward or forwardForward PitchChanging Vehicle Load from Rear to FrontBackward Pitch:Changing Vehicle Load from Front to RearAcceleratingReleasing the brakeReleasing the acceleratorBraking
59Vehicle RollRoll: Vehicle’s weight shifts to the tires located on one side of the vehicleWhich direction is this driver steering to cause this weight shift? What causes a vehicle roll over?
60Vehicle Yaw Yaw Fishtailing No YawYawFishtailingVehicle’s rear tires lose traction and weight shifts to one side while opposite rear wheel moves toward front of vehicle
61Steering For Balance And Control Sit at a safe distance from the wheelUse a balanced hand positionAs speed increases, steering input is reduced for turns and other maneuversPhoto courtesy of ADTSEA
62Changes in Speed Affects Balance and ControlPushing or releasing the accelerator pedal is the primary method to adjust the speed of a vehicleChanges in speed causes weight shifts to front or rear tiresIncreases in speed with steering adjustments causes significant shifts in the vehicle’s weight
63Vehicle LoadVehicle load capacity includes the combined weight of people, liquids and cargo that the vehicle is designed to safely handle.What can affect vehicle load even if the car is empty?Gas! Your car weighs more on a full tank of gas. A gallon of gas weighs about 6 lbs.
64Effect of Vehicle Load On Vehicle Balance What could occur if the driver of this vehicle made a quick steering maneuver?Photo courtesy of AAA Foundation
65Vehicle Over LoadOperating a vehicle above the Gross Vehicle Weight Rating (GVWR) compromises safetyFrame, suspension, brakes and tires are not designed for weights above the rating the manufacturer has set
66Standard Vehicle Reference Points LEFT Reference Point6 inches from line or median3 feet from line or medianRelates a part of the vehicle to some part of the roadwayKnow your vehicle placement within a lane at all timesManeuver in confined places
67Standard Vehicle Reference Points 6 inches from line or curb RIGHT Reference Point3 feet from line or curb6 inches from line or curbRelates a part of the vehicle to some part of the roadwayKnow your vehicle placement within a lane at all timesManeuver in confined places
68Standard Vehicle Reference Points Left Side Reference (3-6 Inches) When you look at the curb, pavement line, or edge of the road, it appears to line up about one foot in from the left edge of the hood
69Standard Vehicle Reference Points Left-Side Reference Point Used for:Lane Position 2Preparing for a left turnDetermining position for parking on the left side of a one-way street (3-6 inches from the curb or line)
70Standard Vehicle Reference Points Right Side Reference PointYour vehicle is 3-6 inches from the curb, pavement line or edge of the road when the line appears near the center of the hood
71Standard Vehicle Reference Points Right Side Reference PointsAre Used:To know where the curb or line is locatedFor Lane Position 3For parking
72Standard Vehicle Reference Points To Position Vehicle Three Feet AwayWhen you look at the curb, pavement, or edge of the road, it appears to line up with the middle of the right- half of the hood
73Standard Vehicle Reference Points Right Side -- Three Feet AwayTo position for a right turn or forLane Position 1
74Standard Vehicle Reference Points Front LimitationTo position 3-6 inches from the line in front of your bumper, stop when your line of sight runs under the side view mirror to curb in frontReference pointLine of sightReference Point
75Standard Vehicle Reference Points Front LimitationYou will need to know where the front bumper of your vehicle is when you are:At intersectionsAt a stopped positionWhen parkingAt a crosswalkSTOP LINE
76Standard Vehicle Reference Points Front LimitationWhen you look at the curb line it appears to line up with the side view mirror
77Standard Vehicle Reference Points Rear LimitationsLEFTWhen you look back over your left shoulder, the curb or line appears to be in the middle of the left rear windowRIGHTWhen you look back over your right shoulder, the curb or line appears to be near the rear window corner
78Standard Vehicle Reference Points Rear Limitations – How They are Used LEFTWhen backing to know where your rear bumper isRIGHTWhen backing around a corner, it’s the pivot point for turning, such as backing into a perpendicular parking space