Simple solution to improve rainy day visibility

You’re driving through a rainstorm and every time the wipers make a pass they smear water across the windshield. The more it rains, the harder it is to see clearly.

Worse, a thin film of fog coats the inside of all the side and back windows. Using the car defroster doesn’t help much—there’s simply too much moisture in the air.

What now?

“Water repellent products can help dramatically improve vision and safety,” said Ron Fausnight, technology specialist at RainX. “They are designed to keep moisture off of glass surfaces inside and outside your vehicle."

Anti-rain products are designed to keep water off of exterior glass surfaces. Anti-fog products keep interior surfaces clear by helping moisture evaporate quickly.

A recent report by the National Safety Council stated three times as many fatalities occur at night than in daytime. Two of the main culprits were impaired vision and longer reaction times.

Water repellent products can increase visual acuity by more than 34 percent, according to a 1997 study by the University of Michigan’s Transportation Research Institute. The study was performed under moderate to heavy rain conditions and also showed drivers improved response times by at least one second.

Nighttime driving also showed better results with the use of water repellent products. Drivers between the ages of 60 and 70 had the most significant improvement.

“Water repellent products prevent water molecules from sticking to exterior glass surfaces,” Fausnight said.

High humidity inside the cabin causes moisture to condense on windows. Anti-fog products spread moisture across the window pane and allow it to evaporate quickly.

“It’s the exact opposite reaction to what occurs with products used on exterior glass surfaces,” Fausnight said.

Why not simply coat the windows with car wax?

“Waxes could leave the surface very smeary and difficult to see through,” Fausnight said. “If the smear does occur, the windshield wiper will have a difficult time removing it and you may need to scrub it off by hand. “

“Also, waxes tend to leave white residue on rubber surfaces and can create a haze on glass surfaces. Polishing compounds in the wax can stick to the rubber surface and can interfere with wiper duties,” Fausnight said.

“Rain and fog repellents do not harm the glass,” Fausnight said. “They may be applied as often as needed. A good rule of thumb is to apply them once a month during the rainy season.”

Fausnight also had these suggestions for keeping your vehicle's windows clear throughout the winter and spring:

• Use anti-rain products for exterior glass surfaces only. Interior requires an anti-fog product that can dissipate moisture and help it evaporate.
• Clean interior and exterior glass surfaces thoroughly before applying window treatment products. Interior glass surfaces often accumulate an oily residue that diminishes the effectiveness of anti-fog treatment.
• Apply window treatment products with a terrycloth or microfiber towel. Spray the towel rather than the surface and wipe it evenly across the glass. Remove excess fluid with a clean, dry cloth to eliminate haze.
• Use your car's climate control system to help reduce moisture, especially in climates with high humidity. The system will help the anti-fogging solution clear glass surfaces faster.
• Avoid getting window treatment products on rubber surfaces. They contain alcohol and can cause rubber to dry or crack.

“Rain repellent and anti-fog products are easy to use and can be applied quickly,” Fausnight said. “I routinely apply them every time my car goes in for oil change.”