Introduction
Sleep loss and disturbed sleep can result in impaired performance. The most sensitive tasks are those which are long and monotonous, such as driving, which become very vulnerable to the effects of sleep deprivation. Both total and partial sleep deprivation lead to decreased performance. As little as two hours of sleep loss will produce noticeable and real decrements. The degree of impairment is directly related to the amount of sleep which is lost. Small amounts of nightly sleep loss can and do accumulate over a period of days. The performance decrements and increased frequency of vehicular crashes seen in those who suffer from severe apnea (a sleep disorder where the person sustains frequent, brief cessations of breathing) reflects the effects of sleep fragmentation of performance. From a safety perspective, it is known that the effects of various performance disrupters accumulate. Thus, minimal amounts of alcohol, when combined with two to three hours of sleep loss, can have profound effects on performance. It has been stated that a single drink taken by a person having a regular sleep cycle two to three hours shorter than needed can have the same effect as six drinks might have on a person with a “normal” sleep cycle.

Sleeplessness is a Major Problem

The scope of “fatigue” accidents (those associated with sleep deprivation) is significant. In Australia where they have defined criteria to identify a crash as a likely “fall asleep” accident, it is estimated that sleepiness or fatigue account for 6% of crashes, 15% of fatal crashes and 30% of fatal crashes on rural 31% of fatal-to-the driver commercial truck crashes were caused by driver fatigue. Most drivers report that at one time or another they have experienced driving while fatigued and momentarily “falling asleep at the wheel,” usually waking up before anything serious happens.

Major Factors in Sleep-Related Accidents

Several Factors influence the risk of having sleep-related accidents. Crashes due to sleepiness occur at times of maximal sleep, i.e., during the night and mid-afternoon “siesta” time. People with undiagnosed sleep disorders (apnea, chronic insomnia, and narcolepsy, or brief episodes of deep sleep). As well as those who are knowingly sleep-deprived, have a higher likelihood of sleep-related crashes. Sleep disorders and sleepiness are common but largely unrecognized in adult drivers. Sleep disorders are more common than diabetes, seizure disorders, and alcoholism among drivers. Sleep apnea occurs in 4-9% of males and 2-4% of females between the ages of 30 and 60, yet less than 5% of these drivers are aware of their condition. One study suggests that people with sleep apnea or narcolepsy perform as poorly as legally intoxicated drivers.

Who is Most Vulnerable?

Certain segments of the population are more likely to have accidents associated with falling asleep. Males have a two to three time’s greater likelihood of being involved in this type of accident. Drivers under the age of 30 are involved in four times the number of fatigue-related accidents. Teenagers, students, and young adults typically have late bedtimes and short sleep cycles, and they more often drive during the times when they are fatigued. Shift workers often are sleep-deprived due to their difficulty in sleeping during the day, or due to having rotation shifts. Commercial drivers have a high exposure to accidents as a result of driving during the late night and early morning hours when a person’s “sleep clock” indicates that it’s time to be sleeping.

Taking a Nap Can Help Prevent Falling Asleep

One easily applied countermeasure to fatigue induced accidents is the nap, or “power nap.” Naps are defined as having duration of 20 minutes to two hours. It is believe that napping is a normal part of the human sleep-wake cycle. There is a biological tendency to fall asleep in mid-afternoon, just as there is a tendency to fall asleep at night. If sleep the night before has been reduced or disturbed, a nap the alertness. Research has shown that naps can have very important benefits, depending on the sleep need and work-rest schedule of thee person. “Power napping,” that is, taking a nap in advance of a period of work that will either last for an abnormally long time, or that will occur at night when sleepiness is naturally greater, can be extremely helpful. Power napping before a “tour-of-duty” for a driver or interrupting the driving task for 20-30 minute nap can be very beneficial in restoring a driver’s alertness and capabilities.

Most drowsiness/fatigue related accidents occur in non-urban areas, generally on roads with 55-65 mph speed limits. Most happen in the early morning hours, with a second smaller peak in mid-afternoon. Most drowsy driver crashes occur on straight sections of roads and with only the driver in the vehicle. A countermeasure to help groggy drivers is the use of “continuous shoulder rumble strips” on the sides of roadways or in advance of obstacles, such as toll booths. They have been shown to make substantial reductions in run-off-the-road accidents, often suspected of occurring from fatigue.

Unusual Shifts Create Sleep Problems

Sleep deprivation accidents don’t happen only with drivers. Factory workers on late shifts can also be subject to the same conditions. OT alleviate the fatigue factors, people working late shifts should maintain the same wake-sleep cycles on their days off as they do during the work week, or they may actually become more sleep deprived. They should sleep in darkened rooms, avoid caffeine consumption three hours before bedtime, and avoid sleeping pills. Employers need to refrain from “rotating” shifts designed to give everyone a “fair break,” and, when possible, schedule more difficult tasks early in the work shift rather than at the end of the shift.

Preventability of Motor Vehicle Collisions

Management and fleet supervisors should establish standards for defensive driving in any type of fleet safety program. The overall performance of the drivers should be evaluated fairly and on a consistent basis. When a collision, the events leading up to the collision, the causes and responsible conditions for the collision, and the post collision events must be carefully evaluated. Driver errors are one of the factors that should be considered. The standards, which should be applied, is the concept of collision preventability.

What is a Preventable Collision?

The National Safety Council. Defines a preventable collision as one in which the driver failed to do everything that they reasonably could have done to avoid it. The American Trucking Association, uses the following rule to determine the preventability of a collision: “Was the vehicle driven in such a way to make due allowance for the conditions of the road, weather, and traffic and to also assure that the mistakes of other drivers did not involved the driver in a collision?

In both definitions the issue is one that relates to defensive driving, not to legal culpability. The fact that a driver, who becomes involved in a vehicle collision, is not legally charged doesn’t mean that the drivers couldn’t have avoided it. When a fleet operation moves from reviewing only collisions where the driver has been charged to reviewing collisions for preventability, a significant step forward has been made in controlling its overall vehicle collision frequency.
Defense Driving

Reviewing collisions for preventability promotes defensive driving. Defensive driving is driving so as to prevent collisions in spite of the incorrect actions of others and adverse driving conditions; such as light, weather, road, traffic, vehicle condition and your physician and mental state. With this as the standard, it is normally true that when a driver makes an error or fails to act reasonably as a result of the errors or other drivers, the collision is considered preventable.

Legal Liability

When judging collisions for preventability or non-preventability it is important to remember the concept is not related to legal liability. While some of the information developed to determine legal liability may be used to determine preventability, is must be understood that legal liability or culpability doesn’t necessarily have any bearing the preventability of the collision.

Drivers sometimes have difficulty in understanding why their collision was preventable when the other party was deemed at fault and cited with a traffic violation. The concept of defensive driving must be explained in detail to newly hired drivers and all drivers need to be reminded that as a professional driver, they are expected to operate their vehicle with defensive driving as a priority.

Preventability is a common practice in many motor vehicle fleets, and along with driver accountability helps in reducing vehicle collision frequency. It may also be used as the basis for Safe Driver Award Programs, safety incentives and other collision prevention programs.

Fair and Honest Decision

Preventability involves making a fair and honest decision. A fair decision may only be reached when all the facts are uncovered and complete details of the collision are obtained. The decision of preventability should be made on the basis on what the driver did or did not reasonably do to prevent or avoid collision. An indication of preventability occurs when there is a citation issued or evidence of a violation of the law. However if there is no violation of citation, it does not make the collision non-preventable. After all the information and reports have been obtained and assembled, the collision must be determined to be preventable or non-preventable. How this is done is and who makes the decision varies from fleet to fleet.

In some companies the fleet safety director, safety director or a supervisor determines if the accident is preventable. In other cases an Accident/Collision Review board makes the decision. To fairly hold drivers accountable they should be trained in the concepts of preventability and in defensive driving. Drivers will not understand the process unless they understand why and how they are held accountable. It must be explained that most collisions result from drier error. The key to the definition to preventability is the word “reasonable” because the driver could have stayed home, but a professional driver’s job is to drive, sot he concept of “reasonable” is applied.

There is often a relationship between preventability and defensive driving. A defensive driver’s profile is:

• Commits NO driving errors.
• Makes due allowance for lack of skill or improper driving practices of others.
• Adjust driving to compensate for unusual weather, road and traffic conditions.
• Not tricked into a collision by unsafe actions of pedestrians or other drivers.
• Alert to collision inducing situations.
• Recognizes the need for preventative action in advance.
• Takes necessary actions to prevent a collision.

Review Board/Committee

If management and the drivers want a more formal process for determining preventability, a Review Board/Committee should be developed. The board is especially effective in deciding borderline cases. Consider the following make-up of the committee:

• Fleet Safety Supervisor or Safety Director (Serve as chairman and is fully trained in collision prevention, preventability, and defensive driving).
• Operations or Transportation Supervisor (Familiar with the operating rules such schedules, routes, hours of work, speed limits and related subjects).
• Maintenance Department Employee (Familiar with the mechanical abilities of the vehicle).
• Two Drivers ,the Fleet Safety Supervisor of Safety Director should present the collision report information to the member and direct the Board/Committee discussion. Advice should be given on preventative measures, but they should not enter into the discussions or decision of preventability other than to clarify the facts of the collision.

Preventable Collisions

Despites the facts each collision must be judged individually, experience over the years in fleet safety has shown certain types of collision are preventable on the part of the driver. Typical or common preventable collision may include:

• Collisions at Intersections
• Backing Collisions
• Vehicle Ahead Collisions
• Vehicle Behind Collisions
• Collisions while Passing
• Collision while being Passed
• Lane Changes/Encroachment
• Railroad/Transit Train Crossings
• Oncoming Collisions
• Fixed Object Collisions
• Pedestrian Collision
• Poor or Bad Weather Collisions
• Collisions Involving Passengers
• Collisions Due to Mechanical Failure
• Parking Collisions
• Collisions Involving Private Property

A listing of preventable collisions may be obtained from the National Safety Council or from The Hartford’s Guide for Determining Preventability of Motor Vehicle Accidents” The listings are intended as a general guideline; as they cannot address every collision that may occur.

Non-Preventable Collisions

Some non-preventable collisions include the following circumstances:

• Struck in rear by other vehicle

            These are Non-Preventable if:

• While proceeding in their lane of traffic at a safe and legal speed.
• While waiting to make a turn from a proper lane
• While stopped in traffic due to existing conditions or in compliance with a traffic sign, signal or officer.
• Struck while legally and properly parked.

Summary

The concepts of preventability and defensive driving are essential to the operation of a fleet safety program. A fleet safety supervisor must diligently work to create awareness of not only the importance of preventability, but also the fleet and defensive driving procedures involved. Providing adequate training as well as holding drivers accountable for preventable collisions will not only reduce the vehicle accident frequency but improve the fleet operations and the company’s bottom line.

Source:The Hartford