Chapter 6 Physical Aspects of Driving

Human Error 90-95% of vehicle accidents are caused by people not vehicles or roadways.

Vision Problems? 90% of driving information is received through the eye Affects of a person’s vision: –Genetics –Fatigue –Smoking –Age –Illness –Alcohol or other drugs

Field of Vision The area you can see looking straight ahead Central vision- looking straight ahead-it’s the area where you see things clearly Fringe vision- outside central vision where you recognize objects but not clearly Peripheral vision- outside of your field of vision where you see motion but not objects

Field of Vision Affects Tunnel vision caused by genetics Other traffic blocking parts of your field of vision Your vehicle’s design can block you vision Illness, even temporary illness can cause vision restriction Age can reduce a person’s field of vision

Alcohol as a Sedative Affects many areas of the body from mental functions to relaxing muscles

Ways Alcohol Sedates the Eyes Slows the pupil, increasing glare and slow glare recovery Relaxing the muscles that control the lens reducing visual acuity Sedating the retina causing problem of color recognition especially shades of darkness while driving Binocular vision: ability of the eyes to focus together on an object Peripheral vision can be narrowed

Other disabilities that may affect a person’s ability to drive includes: Hearing loss- there is usually no increased risk because of visual compensation Physically challenged persons are not normally a greater risk. Safe driving is a mental skill so physical limitations can usually be overcome Age affects all of a person’s senses.

Other disabilities continued Epileptics are allowed to have a class c license if they are on medication and have gone seizure free for one year. Diabetes is a major problem because of the serious effect of high or low sugar Mental ability. The DMV officer can ask for medical referral if he/she suspects an individual’s mental ability may be a problem