Fleets should not be limited to such devices, the ATA said, noting that backup alarms and warning devices could work as well.
Other industry groups also voiced concerns. The Truck Manufacturers Association said it may be better to standardize equipment installation, rather than mandating it.
The Truck Equipment Association said the equipment would cost more than the NHTSA’s estimate of $212 per truck . “Even assuming a labor rate of $50/hour, and no time for compliance determination or placement strategy, a video system is likely to cost between $450 and $835,” the association said.
Advocates for Highway and Auto Safety, an organization of consumer groups, safety activists and insurance companies, called the proposal insufficient. Cross-view mirrors, the organization said, “are clearly less effective than rear-mounted video systems with in-cab monitors.”
Super Singles May Reduce Rollovers
For carriers and owner-operators still considering whether to replace traditional duals with the new generation of wider single tires – marketed as a lighter, more fuel-efficient alternative – there may be evidence of another advantage.
In recent tests, researchers at the Center for Transportation Analysis at the Oak Ridge National Laboratory in Tennessee found a decreased propensity for rollover when tractors and dry vans were equipped with modern super singles over standard duals. A study of the tests was released Nov. 14 at the 2005 International Truck and Bus Safety and Security Symposium in Alexandria, Va.
One of the study leaders, H.E. “Bill” Knee, said researchers put a tractor-trailer with traditional duals, dynamic sensors and outriggers through a series of tests to emulate three events that lead to rollovers: evasive maneuvers, driving around curves with a constant radius, and running off the road. The same tractor-trailer was re-equipped with singles and a wider slider trailer suspension in various configurations and put through the same paces.
The result? In most cases, new generation single tires and slider suspensions reduced rollover propensity, at least in van operations. In evasive maneuvers, the new-generation combination decreased the maximum trailer roll angle per lateral acceleration ratio by 45 percent, a significant amount, Knee said.
A wider suspension spreads out the center of weight, as do super singles, Knee said. “Replacing the standard duals with the new generation of super singles effectively moved out the center of where the weight was on either end by 3 inches,” Knee said. “That gives you a 6-inch wider area. We expected that.”
Some anomalies need further investigation, Knee said. For example, a truck equipped with duals coupled to a trailer equipped with singles and a wider slider suspension performed best in the evasive maneuver test. That may have something to do with driver feel from having dual tires on the tractor, Knee said.
Further tests are planned for tankers and flatbeds, Knee said.
TCA Names Finalists in Driver Contests
The Truckload Carriers Association has named finalists for its Company Equipment Driver of the Year and Independent Contractor of the Year contests.
The 38 finalists were chosen based on safety criteria measured by accident-free miles, driving record, moving violations and hours-of-service violations.