When I first got involved with the Society of Automotive Engineers (SAE) and the Technology and Maintenance Council (TMC), the rule-of-thumb was that between 75% and 90% of a driver’s decision-making information comes visually.
Back in the 1980s, motorized rearview mirrors were the height of new technology. Today, most trucks have motorized mirrors, but primarily for adjustment, not for the reason they were originally promoted. MotoMirror, the originators of the technology, said drivers should use them to scan during right turns. Convex mirrors were still rare and hood/fender, mounted mirrors were yet to be introduced. To spot cars, cycles, and people in the blind spot to the right of the cab, we relied on windows in the passenger doors (often obstructed) and look-down convex mirrors (difficult to interpret quickly).
In the decades that followed, industry developed devices to either improve vision or to alert drivers to objects in blind spots. The technical societies helped integrate them into truck architecture so they would not create any unforeseen maintenance problems. They did not recommend for or against any product, leaving success or failure to the open market.
One development that failed in its initial introduction, but is showing a measure of success as technologies improve, is television. Early versions using “lipstick cameras,” about the size and shape of a tube of lipstick, were mounted on tractors’ front fenders. They scanned the blind spots next to the tractor. Today, microcameras (as used in cell phones) make 360-degree vision possible while improving aerodynamics, and thus fuel economy, by allowing truck builders to eliminate drag-creating outside mirrors. Screens provide greater coverage, adjust for glare, and can be positioned inside the cab.
So why haven’t these cameras taken over? Because tractor and straight truck cabs are narrower than the trailers. Also, Federal Motor Carrier Safety Standard (FMVSS) 111 requires a planar (flat) glass exterior mirror on each side of a truck. Until the National Highway Traffic Safety Administration (NHTSA) amends FMVSS 111, we can supplement old-fashioned mirrors with electronics, but the mirrors must remain.
Overcoming obstructions
TMC has a Recommended Practice, RP 425, Mirror Positioning and Aiming Guidelines, suggesting ways to locate and aim mirrors to minimize and provide the best coverage of blind spots. It also addresses positioning to overcome obstruction by truck bodies and trailers.
Aftermarket suppliers offer vision augmenting devices, including television and radar-based units. Many truck makers have incorporated them and offer them in their data books and option lists.
Several suppliers mount a small TV screen inside the cab near the A-pillar where it can be scanned by the driver as he checks mirrors. Another embeds picture screens in the outside mirrors, turning them on when directional signals are activated. Picture sizes vary from just a few inches at the pillar to a 7-inch diagonal screen placed centrally on the dash. In-the-mirror pictures are limited only by the dimensions of the mirror.
Radar-based crash-avoidance technologies not only augment vision, they react to imminent threats with electronic speed to slow the vehicle. Bendix makes Wingman, its adaptive cruise control that, if it does not prevent an accident, will usually mitigate its severity. Wingman is in Mack and Volvo data books.
Meritor WABCO’s OnGuard Collision Safety System is available on Daimler Trucks’ Freightliner and Western Star trucks. It is always on and not dependent on cruise control, making it more suited to city operations. OnGuard will de-fuel the engine and, when necessary, apply the service brakes for up to 0.35G retardation.
Both units’ adaptive cruise control feature follows at a preset interval in traffic. As traffic ahead slows, so will your truck. As traffic resumes speed, the truck will accelerate up to its preset speed.
Electronic vision augmentation covers blind spots to the sides. Preco’s WorkSight PreView uses radar to scan a 10x10-foot area to the side of the truck. When a car, truck, cycle, or pedestrian is detected in the blind spot, an amber warning light comes on replacing the green “all clear” light. It’s usually mounted on the A-pillar. If the directional signal is activated and something is there, an audible alert accompanies the amber light. If clear, the green light shows.
GE Capital Equipment offers its customers Mobileye’s lane departure warning systems. This vision augmentation device scans the road ahead, detecting lane lines on the road or roads’ edges. It computes the truck’s placement within its lane and issues a visual and audio alert if the truck starts wandering. Turning on the appropriate directional signal cancels the alert.
Nighttime driving
Improved nighttime vision is a key safety factor. In the 1930s, the Interstate Commerce Commission, then the regulator of motor vehicles, determined that automotive headlights were inadequate for 45-mph speed limits, the highest at the time. Tests showed that 7-inch round incandescent sealed beam headlights were the best available and were mandated until high- and low-beam functions were separated in 1958.
Incandescent bulbs remained until 1981, when NHTSA finally allowed deviation from sealed beam headlights. Shaped reflectors directed light more effectively. Then projector lamps put more light further down the road. In the last few years, light-emitting diodes (LEDs) have appeared, providing increased energy efficiency. Several makers now have round and square LED headlamps. Truck-Lite aerodynamic LED lamp capsules were developed for Freightliner Cascadia and International ProStar models and are being developed for other vehicles. LED headlights are in service with our military.
We still get most of our input through our eyes and modern electronics is enhancing our vision to make trucks and those around them safer.
Paul Abelson is a former director of the Technology and Maintenance Council (TMC) of the American Trucking Associations, former board member of Truck Writers of North America, and active in the Society of Automotive Engineers. E-mail [email protected].
