Module 3: Topics 1-3 Vision and Driving Visual Fields Line of Sight/Path of Travel Locating Vehicle Blind Zones

Visual Fields

VISIBILITY Ability to see the roadway and be seen by other drivers and pedestrians

Drivers with poor visual habits: Do not prepare for stops or turns far enough in advance. Do not notice traffic tie-ups in advance. Become trapped behind large trucks, or slow-moving vehicles. Are often surprised. Are unaware of vehicles about to pass. Are unaware of their own speed. Drive with turn signals flashing although they do not intend to turn. Drive with mirrors that are dirty or out of adjustment. Drive with fogged, dirty or partially blocked windows. Become distracted easily. Do not respond to changes in the traffic environment. Recognizing a dangerous driving situation in advance allows time to plan evasive maneuvers. GOOD VISUAL HABITS

90 percent of driving decisions are based on information gathered with the eyes. Area a Driver Can See While Looking Straight Ahead Peripheral Vision Central Vision Focus Vision Motion & Color Changes Targeting (Reading Signs) Viewing Path of Travel FIELD OF VISION

THE FOCAL VISION AREA Located 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 ▪3-5 degrees of useful information

THE CENTRAL VISION AREA Central Vision Area (Inner Fringe) An area 35 to 38 degrees around foveal vision used for: ▪Referencing Vehicle Position to the Roadway ▪Viewing the path of travel

THE PERIPHERAL VISION degrees of useful information Used to see Objects to the side Motion/Movement Changes to the side Color Changes to the side

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

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

EFFECTIVE USE OF VISUAL FIELDS The Three Visual Fields 1.Focal Vision ▪Visual Lead, Targeting, Signs, Signals 2.Central Vision ▪Referencing, Path of Travel 3.Peripheral Vision ▪Motion and Color Changes

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.

Speed Fatigue Drugs Poor weather Darkness Glare Inattention Smoke Age Dirty Windshield Poor Windshield Wipers Poor night vision Night Blindness VISION IS AFFECTED BY

AS SPEED INCREASES Central vision decreases and blurs Peripheral vision decreases Changes in steering exaggerate vehicle movement Vision Field Narrows

WHAT COULD YOU DO TO MANAGE VISIBILITY IN THIS CAR?

THE CENTRAL VISION AT NIGHT The human eyes 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

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

DRIVING AT DUSK Be especially alert at dusk. The sky still may be bright, but objects on the road can merge with shadows and fade into the darkness. Bad weather If the weather becomes too bad, pull off the road to a rest area or parking lot and wait for conditions to improve.

HEADLIGHTS Drive with your low-beam headlights on during daylight hours. During the daylight a vehicle without headlights is visible from about a half mile away. With headlights on, the same vehicle is visible from nearly a mile away. Virginia Law requires low beam headlights to be on whenever your windshield wipes are on. ▪Dim headlights within 500 feet of an approaching vehicle ▪Dim headlights within 200 feet travelling behind another vehicle.

VISIBILITY Advance preparations: ▪Clear and clean inside / outside of windows ▪All lights are working ▪Defroster, wipers and washer are working ▪Adjust mirrors and seat ▪Keep sunglasses handy ▪Remove obstructions in car: packages, things hanging from mirrors Turn on headlights….Day or night Driving with low beams Signal intentions well in advance Avoid driving in another’s blind spot Always wear glasses / contacts if needed Shield from glare with sunglasses

VISUAL SKILLS VOCAB Focal Vision: used to read or identify distinct objects. Central vision: fringe area around the focal vision. It is used to judge depth and position. Peripheral vision: outer vision fields. Motion changes are often detected in the peripheral vision area Target: a fixed object that appears at the end of your path of travel. Path of Travel: where the driver directs and intends for the vehicle to travel. Vehicle operating space: the area around the vehicle which is not visible to the driver.