Aside from taking care of your health, you can take an active role in helping yourself or another senior to drive more safely.

• Find the right car and any aids you need for driving. Choose a vehicle with automatic transmission, power steering, and power brakes. Keep your car in good working condition by visiting your mechanic for scheduled maintenance. Be sure that windows and headlights are always clean. You can also see an occupational therapist for special driving aids that can help with physical problems.
• Take it slow and give yourself plenty of room. If cars are passing you on both the right and left lanes, you may be driving more slowly than you used to. Move into the slow lane so others can pass you safely. Also, to avoid problems if the vehicle in front of you stops suddenly, stay back about two car lengths. Be sure to yield the right of way in intersections. Older drivers also have a large number of accidents at intersections when making left turns. It is best to avoid them altogether by making successive right turns and keeping going around the block or blocks to get to your destination.
• Avoid distractions. In general, many accidents happen because of distractions like talking on the phone, tuning the radio, eating or drinking, reaching for something, turning your head to talk with a passenger or looking around at the scenery instead of the road. Even a few seconds of taking your mind off driving can be precarious.
• Avoid uncomfortable driving situations. Many older drivers voluntarily begin to make changes in their driving practices. For instance, you may decide to drive only during daylight hours if you have trouble seeing well in reduced light. If fast-moving traffic bothers you, consider staying off freeways, highways, and find street routes instead. You may also decide to avoid driving in bad weather (rain, thunderstorms, snow, hail, ice). If you are going to a place that is unfamiliar to you, it is a good idea to plan your route before you leave so that you feel more confident and avoid getting lost. Online services such as MapQuest, Google Maps, and Yahoo Maps can be very helpful.

Source: Helpguide.org