Waste collection fleet owners should have a serious look at their own trucks and evaluate the options to provide automatic backup braking to their drivers.
By Lorne Hull
A backing accident happens much more than most trucking companies realize; although current insurance company estimates put the average repair cost at approximately $8,000 per incident, there is a darker and often more tragic cost when the object hit by a backing truck is a person. Five hundred people die and another 15,000 are injured every year from backing accidents.
How do experienced truck drivers suddenly find themselves involved in a collision, or worse yet, a personal injury backing accident? While trucks can be driven forward with relative safety, a whole new set of challenges are presented to the driver when backing up:
- Mirrors and/or video cameras can present different depth perspectives, which can result in unwanted contact even if there is only an inch or two perception difference
- Momentary cab distractions such as radio calls, phone, audible alarms, etc.
- Sudden movements in front of the truck that momentarily distract the driver
- View obstructions such as bushes, signs, trees, gates, etc.
- Hard to see physical obstructions in the path such as pallets, curbs, metal/wood debris, etc.
- Low visibility conditions caused by weather, night, poor lighting, etc.
- High activity area requiring an additional level of awareness of the area immediately behind the truck (objects moving into the path of the truck)
- Distracted pedestrians wandering into the path of the moving truck
- Miscommunication between a guide and driver
With an awareness of the above challenges, the complexity of modern waste/recycling truck cabs add yet another layer of potential distractions that can momentarily divert driver’s attention from the path of a backing truck. The left mirror, right mirror and video camera above the driver require constant head and eye movement that can add to the crucial reaction time as described in the following details.
A Backup Collision Situation Occurred … How Far Will Your Truck Continue Before Stopping?
It can and will happen to the most seasoned driver—an unexpected object has appeared in the path of the truck and the brakes must be applied hard and fast. There are a few factors that determine the distance traveled before the truck will come to a full stop. The stopping distance of a vehicle depends on: perception time, reaction time and event distance (Note: For slow speed backing ~ 5 mph, we assume braking distance is not significant)
The time it takes for a driver to see or hear a hazard condition and to recognize immediate action is required. In the best conditions with a hazard developing in front of the driver, it can take from ½ to ¾ of a second to make the conscious decision to apply the brakes. If the driver is rotating his gaze between mirrors and a video camera as (for instance) an object presents itself immediately in the path of the unobserved corner of the truck, the most experienced driver could take one to two full seconds to recognize the hazard and then make the decision to respond.
Once a decision to react has been made, the reaction time is the time it takes the driver to remove his foot from the accelerator (if applied) and to fully apply the brakes. The estimated time for activity is ½ to one second.
Based on perception time and reaction time, this is the distance the truck will travel before stopping. Any object suddenly presenting itself within this distance will be struck. This distance is a directly proportional to the backup speed of the truck.
Figure 1, is a simple reality of math—any object within the event distance under the parameters selected will be hit. The Event Distance chart provides an insight to accidents as well as injuries that can occur to the most experienced drivers. The development of electronic automatic backup braking has made this chart moot.
Automatic Backup Braking … Electronic Technology that Prevents Accidents
There is now technology that both detects objects in the path of a backing truck and reacts instantly by automatically applying the brakes. This technology combines object detection and applies the brakes automatically, thus reducing event distance from a number of feet to fractions of an inch.
The detection can be infrared (IR), microwave, or ultrasonic but it is important that detectors are designed and configured for the following characteristics:
The system is automatically activated only when the truck is in reverse.
Focused Coverage Area: It is important to limit the coverage to an area directly in the path of the truck. For a waste removal truck that would be approximately 12″ or less wider than the truck, and a minimum of 60″ behind the truck without actually contacting the ground. This is important because excessive false alarms will annoy the driver and create unnecessary delays in a simple backup procedure. A sample sensor setup currently used in waste/recycle trucks is illustrated in Figure 2.
There should be an override or temporary defeat control when the driver acknowledges the object behind setting off the sensors during the backup maneuver (for example, dock, refuse container, etc).
Any override or defeat setting must be reset back to normal operation as soon as the backup procedure is finished. Typically an automatic backup braking system will reset as soon as the reverse gear is not engaged.
Never install any switch that can turn the automatic braking system completely off. The automatic braking will become a reliable tool to the drivers and the unknown absence of this feature could have severe consequences.
If Your Fleet Does Not Have Automatic Backup Braking … What’s Stopping You?
Benefits in using sensor technology to prevent accidents through automatic braking have been recognized by both government and car manufacturers. In March 2016, 20 auto manufacturers agreed to make automatic braking technology standard on all vehicles by 2022. Automatic backup braking on industrial trucks has not benefited from the same level of attention from either manufacturers or fleet owners. Many truck manufacturers will provision third party automatic backup braking systems upon request and many of North Americas largest municipal operated waste collection trucks are now equipped with third party automatic backup braking systems. As the newspaper headlines indicate in Figure 3, there are many waste/recycle trucks still operating in residential areas without the additional level of safety provided with automatic backup braking.
We have seen how bells, alarms, video cameras or flashing lights will not guarantee to stop a truck quickly; however, automatic backup braking will. The cost of adding a third-party automatic backup braking system is a fraction of the average damage incurred during a collision excluding tragic consequences if a person is involved.
Until government and the trucking industry have the opportunity to catch up to the automatic backup braking technologies available, waste collection fleet owners should have a serious look at their own trucks and evaluate the options to provide these additional safety benefits to their drivers.
Lorne Hull is Director of Sales and Marketing for Global Sensor Systems, Inc. (Mississauga, ON). For more information, visit www.globalsensorsystems.com.