Hydrophobic Windshield Treatments
If you are like me, the worst time to be driving is at night in the pouring rain. It's like driving into a wet sack of coal! When another vehicle approaches, the glare of their headlights can be blinding. When driving is a necessity rather than a choice, what's a driver to do?
A study by the University of Michigan Transportation Research Institute concluded that hydrophobic windshield treatments can result in significantly improved driver visual performance.
In the study researchers found that treated glass increased drivers' visual acuity by as much as 34 percent and cut response time to a test target from four seconds to three. (A single second represents a significant margin of safety, since it translates to about 17 meters at 60 km/h.)
There are a number of brands of these coatings on the market and may be found at any auto parts store. They are applied to clean auto glass and then repel water, causing it to bead and stream off making it easier for wipers to keep the windshield clear and for you to see. They also help to repel snow and sleet and make it easier to scrape ice off.
A bottle is relatively inexpensive, costing between $5 and $10. A single treatment seemed to last me about a month and there are many re-applications in the bottle. The only difficulty I found was in cleaning the windshield well before applying it.
The maker of Rain-X did not answer my inquiry about proper pre-treatment cleaning.