Obviously, good visibility is paramount to driving safety. As I have noted in previous columns, research finds that 90 percent of all driving decisions depend on vision alone.

A clean windshield — inside and out, good wiper blades, and a windshield washer system in proper working order and filled with the appropriate windshield washer solvent are the keys to unimpaired visibility and driving safety.

A clean windshield reduces the sun's glare and decreases the glare of other headlights at night. Glare is a serious problem because it reduces a driver's ability to see clearly. At times, glare can even cause temporary blindness.

A dirty windshield worsens the problem because dirt, streaks and smudges are magnified by glare and scatter light rays, thus blinding the driver.  

Worn out wiper blades impact visibility. Because they can't effectively clear the windshield of rain, snow or debris, a driver's vision will be blurred.

Over time, the rubber in the wiper blades can wear out, lose its flexibility and become rigid, develop chips and change shape. The result: streaks on the windshield that obscure and blur vision.

Wipers also can become bent and misaligned, causing an inadequate wipe as well as an annoying noise.

Wipers build up a thin layer of grime, especially after a dry spell, which keeps the rubber blade from contacting the windshield, smearing the glass and decreasing visibility. To avoid this and improve wiper performance, keep the blades clean by wiping the length of them with a paper towel, cloth or sponge moistened with water, baking soda or auto glass cleaner.

Regularly inspect wiper blades and replace them when necessary.

Some tips and techniques for keeping a vehicle's glass clean.

Mix a half cup of baking soda with a quart of warm water. Apply with a dryer sheet wrapped around a sponge.

Use ordinary household glass cleaner. These typically contain ammonia, which tends to leave streaks, so a second application may be required. Professional glass cleaners contain no ammonia, but are more expensive.

Mix equal parts of vinegar and warm water and use a spray bottle to apply, then wipe the glass dry with newspaper. The newsprint ink works as a polishing agent.

Be sure to clean the inside of the glass as well, especially if the driver or passenger smokes. Cigarette and cigar smoke can cause a film to build up on the inside of the windshield, affecting clear visibility.

Before cleaning side windows, roll them down partially so the area along each window's top edge can more easily be cleaned.

Apply the cleaning solution to a soft towel or cloth rather than to the glass itself. This will prevent the solution from getting on surrounding areas.

I clean the outside glass using a side-to-side motion. For the inside glass I use an up-and-down motion. By doing so, if I have any streaks, I can determine which side of the glass they are on.

Finally, don't forget to clean all side mirrors.

Among the methods for removing “baked on” road and bug splatters, tree sap, bird droppings and other stubborn substances:

Wet a dryer sheet and wipe away.

Pour on seltzer water, vinegar, soda or cooking oil to loosen the caked-on “material” and then wipe away with a cloth.

Carefully remove using a new razor blade and light pressure so as not to scratch the glass.

The reason that “foreign matter” on windshields is often difficult to remove is because glass is porous. When a bug hits the windshield, by way of example, its “gook” is pressed in those open pores and baked from the heat of the sun.

A number of rain-repellant glass products are on the market designed to improve wet-weather visibility by repelling rain, sleet and snow. The repellants also help reduce the adhesion and build-up of water spots, bugs, tree sap and road grime.

Such products work by filling in the microscopic peaks and valleys on the windshield's surface, causing water to bead so the air passing over the glass can help remove it.

David Kolman is a veteran truck communicator, keynote speaker and long-haul trucker. Commissioned as an Honorary Colonel on the Kentucky governor’s staff for his work promoting traffic safety, he actively participates in trade associations and reports news and information about the trucking industry for broadcasting and print media.