By Paul Abelson
senior technical editor
About 90 percent of the input we use to make driving decisions is visual. If you can’t see, you can’t drive. In the future, electronics may change that, but now that’s the way it is. Diminished vision shortens available reaction time and creates otherwise avoidable situations.
A clean windshield is critical to good vision. So change wiper blades when they start to streak. As wiper blades age and crack, they leave streaks and can smear bugs as they try to clear the glass.
Keep windshield reservoirs topped-off with high-quality washer fluid. Even though it’s more expensive, use glycol-containing fluid in winter to melt ice and snow, and bug-dissolving fluid in summer to keep windshields from smearing. They are worth the price.
Polymer coatings for windshields first appeared in the 1970s. When applied to clean glass, they prevent water from adhering to windshields, side glass and mirrors. Whether raindrops or snow, water will bead up and not distort vision. It can blow away at highway speeds. Rain-X is the most popular of those coatings but there are others. Follow directions when applying. The first application should last for a month or more.
Rostra and Microheat make windshield washer fluid heaters. Hot fluid melts ice from wiper blades and windshields, and helps dissolve bugs in summer. Both Microheat’s HotShot and Rostra’s Safe-Vue can be retrofitted.
Ice can jam wiper frames. Rubber-covered winter blades keep ice from getting into the frames and jamming them, allowing blades to flex and follow the contours of today’s curved windshields.
You can replace your current blades with heated windshield wipers, which are effective in preventing ice and snow buildup. Everblades are offered as a complete kit for about $80.
A new frameless wiper blade design is now available. It has the blade molded around a strip of spring steel, an internal frame. Most have an aerodynamic lip so air pressure holds the blade to the glass.
Defrosting the outside of the windshield and demisting the inside are tasks still best done with the OEM heater and defroster system. When set to defrost, the air conditioner dries the air. Start with the heat control at high when running just defrosters. When you winterize, make sure your heater core, ductwork and air outlets are clean and free of debris. A small dashboard-mounted, hard-wired or battery-powered fan can help circulate defroster air, to speed demisting.
Federal Motor Vehicle Safety Standard No. 111 sets standards for heavy trucks’ mirrors. It requires 50 square inches of flat mirror on each side of the cab. A circular mirror 8 inches in diameter or a square less than 7.5 inches per side qualify but are impractical today.
Today’s West Coast mirrors are at least 7 inches by 16 inches, or 112 square inches, more than double the requirement. In the ’70s, Moto Mirror introduced motorized West Coast mirrors. They keep tandems or the rear of the trailer in view when turning and backing. Stationary mirrors show just the broad side of the trailer. Motorized mirrors can be used with straight trucks to allow an area scan before backing up.
West Coast mirrors seem to attract splash and spray. Rain obstructs and distorts vision. If you let salt spray build up, it blocks vision. For about $150, you can clean your mirrors with the push of a button while you’re heading down the road. The Air Vizion AV 1000 uses compressed air to clear water from the glass face.
Convex mirrors let us see tandems and traffic when turning. Deep convex fender mounted mirrors give us awareness of hazards in blind spots at the right front corner and along the right side.
Mirror placement and aim are critical to having mirrors function properly. In a survey done by the Technology & Maintenance Council, many trucks had mirrors mounted too close to the tractor. That meant the driver’s vision was blocked by the front of the body or trailer.
TMC Recommended Practice 425, “Mirror Positioning and Aiming Guidelines,” states that “the inner edge of the mirror is at least one inch (outside) of the widest portion of the load or cargo box on the truck or trailer. The preferable position is for the mirror to be as far (outside) as is practical, considering causes of physical damage to the mirror.” The RP has diagrams and guidelines for aiming mirrors.
Many drivers aim outside mirrors with the horizon halfway up the mirror. This wastes much of the mirror area by including too much sky, where there are no hazards. Place the horizon within 1 to 1.5 inches, depending on mirror height, of the top edge to increase coverage of blind spots close to the sides of the truck. Objects near drive wheels may be seen with mirrors aimed down. They can be missed if the mirrors are level or aimed up.
No matter how good a mirror may be, its field of view will always be limited by its size or blocked by some portion of the load.
Setting aside cost considerations, for the ultimate in rearward vision, especially when backing, nothing beats closed circuit television. Several companies make them. Many are as useful in low-light conditions as they are in broad daylight. New cameras differentiate subtle differences and eliminate the annoying halo effect that can hide details. Newer screens have overlays showing distances and center lines. Be sure to locate the monitor where glare will not be an issue.
The Iteris AutoVue Lane Departure Warning System alerts drivers when they are drifting out of a lane. At several fleets, the system was so popular, drivers insisted that management equip all trucks.
The Eaton VORAD collision avoidance system, used by itself or with any of several makes of side blind-spot detection devices, has proven its worth in fleet use during the past decade. One fleet using VORAD reported a significant reduction in crashes because of following too close. At sides or rear, radar-based proximity warnings make lane changing safer and help backing. These devices carry a high initial price, which can be offset by lower insurance premiums because of fewer accidents, smaller claims when crashes do occur, and less downtime.
Domestic light-emitting diodes – LEDs for short – are now value priced and virtually burnout-proof. There are still problems with offshore knock-offs. LED stop lights come on two-tenths of a second faster than incandescents, giving following vehicles an extra 17 feet to stop or slow enough to avoid crashes.
Modern plastic aerodynamic headlight covers improve fuel economy, but they become scratched and cloudy from road grit and chemicals in the air. Truck washes can also scratch the plastic. Light is increasingly diffused and absorbed as the plastic ages, reducing how much light goes where it’s needed. You see less and less, but the change is so gradual that you don’t notice it.
Clear Solutions LLC has dealers around the country that recondition plastic headlights, restoring them to a like-new state, improving driver vision.
Whether visual or electronic, improved driver vision increases situational awareness and will pay dividends through lower repair and insurance costs. LL
Paul Abelson may be reached at email@example.com.