1. Virginia Department of Education
Module Three
Vision and Driving
Establishing a Safe Lane Position
Accelerating and Braking
Vehicle Reference Points

2. Review Mod 2 ________________________
Establishing a “Starting Procedure”
Adjustments
Seat
Mirrors
Seat belts
Head Restraint (if adjustable)

3. Left foot “rests” on dead pedal
Foot Pedals
Dead Pedal
Brake
Accelerator
Right foot pivots between accelerator and brake
Left foot “rests” on dead pedal

4. Basic Maneuvers -- Steering
Holding the upper half of the wheel can result in excessive steering, air bag injuries, and upper body fatigue
Hands located on lower half of the
wheel offers:
Relaxed, balanced control
Reduces unwanted steering wheel movement
Improves stability by lowering the body’s center of gravity

5. Maintaining Vehicle Balance
Vehicle balance is the distribution of the weight of the vehicle on the tires
Optimum balance is reached when the vehicle is not moving or is moving in a straight direction at a constant speed
As soon as the vehicle accelerates, brakes, or turns, the balance is changed and the weight transfer changes the size of the tire patches
**Pitch- Accelerate & Brake **Roll- Left to Right **Yaw- Fishtail

6. Using Lane Position to Maximize LOS
Select the lane position that gives you the best line of sight and safest path of travel
Lane positions are based upon an average lane size of 12-feet wide, and a vehicle 6-feet wide 1 2 3 4 5

7. Topic 1 - Vision and Driving
Drivers base about 90% of all driving decisions on what they see, and % on what they hear or feel
Drivers must be able to see far enough ahead to make good decisions about speed, lane position, signs, signals, markings, and potential hazards
Drivers should search at least 20 seconds ahead in the path of travel to evaluate potential risks

8. Drivers must learn proper visual skills
Drivers must learn proper visual skills. Proper searching is a learned skill.
“The eyes don’t tell the brain what they see, the brain tells the eyes what to look for.”

9. What does your vision score mean?
If you have 20/20 vision, you can see clearly at 20 feet what should normally be seen at that distance
If you have 20/70 vision, you can see clearly at 20 feet what should normally be seen at 70 feet.

10. Visual Testing
Visual acuity is the measurement of the details which can be seen in optimal light conditions

11. Drivers must be able to see near and far--close enough to read the speedometer, and far enough ahead to see/adjust for hazards

12. Effective Use of Visual Fields
The Three Visual Fields
Focal Vision
Visual Lead, Targeting, Signs, Signals
Central
Referencing, Path of Travel
Peripheral Vision
Motion and Color Changes

13. Focal Vision
Focal vision is primarily responsible for object recognition
Focal vision is limited to the central two degrees of vision
Focal vision allows one to see clearly in order to recognize objects and read displays

14. Central Vision An area 35 to 38 degrees around focal vision used for:
Referencing Vehicle Position to Roadway
Viewing Path of Travel

15. Central Vision at Night
The human eye’s field of vision is much smaller without the help of natural light
Depth perception, visual acuity, and color recognition are all compromised at night
Minimize glare by looking at the bottom right of the road to avoid approaching headlights
Keep it dark in the car
Slow down to give yourself longer to react

16. Approximately 90 degrees of vision to each side
Peripheral Vision
Approximately 90 degrees of vision to each side
Increases total field of vision to about 180 degrees and is used to see:
Objects to the side
Movement and color changes to the side

17. Peripheral Vision and the Driving Task
Drivers use peripheral vision to:
See color and object movement
See signal changes, road signs, warning lights on the dashboard
Monitor traffic
Stay within the lane

18. Night Time Peripheral Vision
Is reduced dramatically due to lack of light to retina and glare
While Focal and Central Vision are also reduced, they become more critical for searching for problems

19. Vision is Affected by Smoke Age Glare Dirty Windshield Fatigue Drugs
Poor Windshield Wipers
Poor night vision
Night Blindness
Glare
Fatigue
Drugs
Poor weather
Darkness
Speed
Inattention

20. Depth Perception
Need both eyes to judge the distance between two objects
Depth perception allows you to:
judge gaps in traffic when turning, merging, or passing
judge distance when approaching a vehicle or obstruction
Are these line parallel?

21. Signs of Poor Depth Perception
Stop too far from the stop line or intersection
Stop too close to vehicles ahead
Move into gaps that are too small
Look for gaps that are larger than needed to perform a maneuver
Follow other vehicles at unsafe following distance
Hit parked cars when parking
Have “close calls” when entering traffic, passing, etc.

22. Speed Affects Vision Central vision decreases and blurs
Peripheral vision decreases
Changes in steering exaggerate vehicle movement
VISION FIELDS NARROW

23. Ways to Improve the Vision Fields
Clean windows—inside and out
Clean lights—be sure they work
Check defroster and wiper blades
Remove any objects that interfere with vision
Adjust mirrors properly
Keep sunglasses and windshield scraper in vehicle

24. Line of Sight
Line-of-sight is the distance you can see in the direction you are looking

25. Line-of-Sight (LOS) Restrictions
When vision is blocked, speed and position adjustments may be needed until LOS is restored

26. The 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

27. Examples of Path-of-Travel Restrictions
Space is not available for the vehicle
Narrow lane and no shoulder
Vehicle stopped or blocking intersection

28. “Target” Far Ahead in the Path of Travel
A “Target” is an object or area far ahead in the center of your path of travel
Identify the target in this driver’s path of travel

29. Target AREA Provides the BIG Picture
The Target area is the area drivers must scan to the left and right of the target
Target Area

30. Advantages of Targeting
Easier to track vehicle in a straight line
Driver looks far ahead of the vehicle, and at the same time gathers information close to the vehicle
Driver can plan ahead to better manage risks
Targeting develops visual skills essential for managing traction loss and steering control

31. Effect of Speed on Vision and Steering
VISUAL FIELDS NARROW
As speed increases:
central vision narrows and blurs
peripheral vision decreases
changes in steering will cause exaggerated vehicle movements

32. Effect of Speed on Vision
As speed increases, look farther ahead of your vehicle to increase line of sight (LOS) and search your path of travel (POT) to:
allow more time to gather information;
lengthen total visual field, giving more time for adequate response; and
place more space between other users and your vehicle so sudden steering changes are held to a minimum.

33. Determining Following Intervals
Fixed Object or Shadow
One Thousand One
One Thousand Two
One Thousand Three
One Thousand Four

34. Time, Speed, and Distance Time, Speed and Distance on Dry Pavement
Vehicle Ft./Sec.
Speed Travel
Following Interval
2 Sec Sec Sec.
1/2 sec 3/4 sec Total
Steer Brake Brake
Dist Dist Dist.
30 mph f/s
88 ft ft ft.
22 ft ft ft.
40 mph f/s
116 ft ft ft.
29 ft ft ft.
50 mph f/s
148 ft ft ft.
37 ft ft ft.
60 mph f/s
176 ft ft ft.
44 ft ft ft.
70 mph f/s
208 ft ft ft.
52 ft ft ft.
Formula for approximate feet per second traveled:
Speed + ½ speed = FPS traveled

35. Following Intervals
2 Seconds… Allows driver time to steer out of problem areas at all listed speeds on a dry surface and stop before problem areas at speeds under 35 mph.
3 Seconds… Allows driver time to steer out of problem areas at all listed speeds on dry surface and stop before problem areas at speeds to 45 mph.
4 Seconds… Allows driver to steer out of problem areas at speeds up to 65 mph on dry surface and stop before problem areas at speeds to the legal limit of 65 mph.
Most factory equipped passenger car tires are not designed to steer out of problem areas at speeds beyond 75 mph. At such speeds, speed rated tires are required due to increased tire heat and reduced traction caused by excessive sidewall flexion--especially on curves or when turning.

36. Topic 2- Accelerating and Braking
Covering the Accelerator
Used for a smooth transition from braking to accelerating
Allows the vehicle to coast which may speed up or slow down the vehicle
Permits the driver to be prepared for any needed acceleration

37. Acceleration Techniques
Progressive, Smooth Acceleration
Heel pivots foot from the brake to the accelerator
Gently apply pressure to the accelerator pedal to gradually increase speed to minimize backward pitch and maintain vehicle balance
How do you know if you are and smoothly gaining speed?

38. Acceleration Techniques (cont)
Thrust Acceleration
Typically used when passing or merging into higher speed traffic
Greater pressure is applied to accelerator pedal to rapidly increase speed without losing tire traction

39. Braking Techniques Smooth braking technique:
Is a trait of a skilled driver
Saves wear and tear on the brake system and tires

40. Methods to Reduce Speed
Release the Accelerator
Most frequently used method to slow vehicle speed
Gradually reduce pedal pressure to avoid abrupt changes in speed

41. Methods to Reduce Speed
Controlled Braking - When releasing the accelerator is not enough
Check the rear view mirror
Release accelerator and apply smooth, steady pressure on the brake pedal
For 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

42. Methods to Reduce Speed (cont)
Threshold Braking in an Emergency
Slows the vehicle as quickly as possible without locking brakes or losing traction
Release accelerator while checking traffic behind
Exert forceful pressure on brake pedal and you will feel the vehicle weight shift forward
If you feel the wheels begin to slide, ease the pressure on brake pedal so the tires can begin rotating again

43. Methods to Reduce Speed (cont.)
Trail Braking – Used for Sharp Turns
Occurs 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

44. Trail 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

45. Anti-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.

46. Anti-Lock Braking System (cont)
If steering control is lost, the vehicle skids in a straight line wherever it is going ABS is an anti-lock/anti-skid brake system that allows the driver to steer during hard braking

47. Anti-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 system
To find out if a vehicle is equipped with ABS, turn on the ignition and check the instrument panel for the ABS indicator light

48. Practice Activating ABS
In a parking lot, go mph and execute an emergency stop to engage ABS
Keep your foot firmly on the brake even when you feel the brake pulsate and/or hear noise
This computerized pumping action can pump the brakes up to 15 times per second