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25 and starts to make errors. Stress is the body's reaction to a among airports. A maximum of 12 h of duty time was men- change that requires a physical, mental, or emotional adjust- tioned by several respondents. General aviation and non-hub ment or response. To better manage stress, research indicates airports, where the norm is to have but one daily shift of that one must take care of the physical, mental, and emotional maintenance operations, would be most likely to utilize that components of stress (38). Factors such as age, proper nutri- length of time. Beyond 12 h of duty time, fatigue becomes a tion, and taking medications were mentioned by respondents factor for professional drivers (24). At larger airports, where to the questionnaire as having an affect on one's ability to multiple shifts are staffed, the suggestions were to limit the manage stress. Several individuals made note of the eyestrain employees to one normal shift or to no more than 10 h, and/or caused by blowing snow and bright lights as a major factor to stagger the staffing over several shifts. Several airports contributing to fatigue. cited policies of 4 to 6 h on and 4 to 6 h off. Blowing snow and brighter than normal lights constitute Sending one shift home early in anticipation of a later part of the operating environment the drivers encountered recall is practiced by several airports. However, the assump- during winter operations. Because snow plows can operate at tion is that shift personnel being released early will go home speeds up to 40 mph during snow removal, the need to see as and get some rest. A drawback to the procedure is that often far forward as possible requires lights that will illuminate as far the individuals are not able to get rest due to family activity, as possible, which means more powerful and brighter lights circadian rhythm functions, or other circumstances, so they than normal vehicle headlamps. Together, the bright vehicle return to work fatigued, provided the roadway conditions lights and runway lights set at high settings contribute to driver allow them to return. The duty time limitations can be imple- fatigue. Vehicle engine and wind noise, climate control fans mented more easily if the airport provides rest and food facil- blowing, and the chatter of various aviation radio frequencies, ities for its employees at the airport. all contribute to environmental factors causing fatigue. When one adds the alternating cold and heat of the outside and inside cabin environments into the situation, one can understand Provide Sleep or Rest Facilities why those factors were cited by respondents as contributing During major winter storms, it is not uncommon for airport to fatigue and driver impairment. employees to remain at the airport for days. Several small and non-hub airports indicated they have sleeping quarters or Snow equipment manufacturers have only recently cots set up in the maintenance facility. However, a good rest attempted to address in their vehicle designs some of the environment was deemed just as important to the operators. environmental factors stated earlier, as well as some of the At primarily medium-to-large-sized airports, resources exist ergonomic factors that have plagued drivers in the past. Quite to secure lodging for their personnel at local hotels, which a few respondents mentioned vehicle design parameters as several do. impacting their performance. It was clear by the survey response that some airports are still using old equipment, in that respondents cited the following as affecting their abil- Provide Food and Drink ities: controls were not laid out well, the seats were uncom- fortable, the condition of the cabin was old and worn, there Survey respondents indicated the provision of food was wasn't room to move around in the cab, some vehicles still deemed an important factor in combating the symptoms of had manual transmissions requiring constant shifting, and the fatigue, and it also has been identified by the FAA in its vehicles experienced frequent breakdowns. Vehicle design research. The FAA has noted in its fatigue countermeasure parameters are discussed in greater detail in chapter eight. brochure that eating frequently and wisely to prevent low blood sugar reduces the effects of fatigue (15). FATIGUE MITIGATION AND MANAGEMENT Some airports provide food or have it catered as a way to ensure proper nutrition for their employees. It also serves as Given that there are many different factors causing fatigue, a way to reduce the amount of time away from snow removal they can be grouped into common attributes, as can the operations. Other airports will provide a snack pack for responses for mitigating or managing them. The groupings employees to take with them in the vehicle. Making sure the are best described as the following: limit duty time, provide coffee pot is in good working condition is vital at many air- sleep or rest facilities, provide food and drink, provide frequent ports, though several respondents specifically mentioned the or adequate breaks, rotate assignments, consider ergonomic caffeine-potent "energy drinks" as an alternative. In a pre- factors, and other. liminary study, a specially formulated energy drink was found to have a consistent effect on sleepiness, lane keeping, and Limit Duty Time speed choice in traffic (39). Limiting duty time was the most frequently mentioned sug- Although caffeine can increase vigilance and decrease the gestion for mitigating fatigue. The length of duty time varied feeling of fatigue, it can also postpone sleep (whether desirable

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26 or not), impair the quality of the sleep that one gets, and can Consider Ergonomic Factors increase one's heart rate and blood pressure. Too much caffeine and operators will have difficulty recovering from long hours Previously noted as a fatigue factor was the design and/or of work because their rest or sleep time will not be very rest- ergonomics of the vehicles used in winter operations. It is no ful. For restful sleep, the recommendation is for caffeine to be surprise that a solution to that issue is to have newer vehicles avoided for 6 h before going to sleep. A snow plow driver with better seats, increased comfort, reduced noise levels, may find this difficult to do when completing a 12-h shift and and better ergonomic layout of controls. having to return the next day. Other Caffeine normally has its peak effect 1 to 3 h after being consumed. Individuals who regularly use caffeine develop a Under the last broad area of survey response are a number of tolerance to it and eventually need more caffeine to feel the technologies and suggestions that point toward both the orga- same effect. This makes it more difficult to use caffeine nization and the individual for managing the fatigue factors "strategically," because a lesser effect will occur when it is associated with winter operations. The simple act of rolling needed the most. Individuals who do not regularly consume the window down to get cold air, or keeping the plows going caffeine will be more sensitive to its effects and, therefore, and not stopping, using radio chatter and humor to keep spir- will find it easier to use caffeine strategically. Sensitivity to its up, and talking to oneself to remain focused, all point caffeine also changes with age so that as one gets older, one toward the motivational aspects of combating fatigue. One tends to get more of a "lift" from the same amount of caffeine. respondent suggested as a motivator to remind every one of the overtime pay they would receive. Provide Frequent or Adequate Breaks Although self-motivation can be a deterrent to fatigue, Based on the comments received in the survey, long hours are organizational efforts to manage fatigue are more effective. the expected norm during winter operations, especially at Having supervisors closely monitor the efforts of the snow smaller airports that have fewer employees than larger airports. removal crews for signs of fatigue; upper management sup- The comments received suggest that airport organizations do port of policies to provide duty limits, adequate breaks, job not typically plan increases in the number of employees dur- rotation, sleeping quarters and food; or reducing stress and ing winter operations. Instead, they view the snow event as an managing expectations of personnel through budget expendi- anomaly that is to be managed using normal staffing levels and tures and well-planned options for bringing in support per- budgets. A normal solution to inadequate number of personnel sonnel are all examples of how an airport can indirectly reduce is to increase existing employee hours but try to give them gaps that exist in the risk factors involved in winter operations. more frequent rest breaks. A second solution is to enlist build- A well-thought-out SMS can create an organization that will ing maintenance or other non-airfield personnel. That activity support such efforts. can increase the risks of a vehicleaircraft incident, however, because the individual's experience and training in airfield The following case examples of fatigue are from the ques- operations may have lapsed. A best practice would be for air- tionnaire responses. port management to have an integrated training regime to keep individuals current in airfield operations. At one large-hub airport, the approach to mitigating fatigue factors is as follows: Frequent breaks were cited by a majority of responders as the way to mitigate the effects of fatigue factors. After getting Personnel are on duty around-the-clock during a snow event. Bunk, locker rooms, and shower facilities are provided. Crew adequate rest, the FAA has identified that standing up, stretch- scheduling was based on previous US DOT over-the-road regu- ing, and walking around as much as possible is a prime method lations. During extended events, the full crew is broken into half for countering the effects of fatigue. Associated with taking or thirds to facilitate rest periods. Personnel are on the clock frequent breaks is the suggestion made by many survey respon- when they are sleeping. At airport insistence, equipment manu- facturers have allowed vehicle operators to have input into the dents to break up the monotony of snow removal operations design of new operator cabs that feature improved ergonomics, by rotating assignments or jobs. better climate control, improved visibility, and user-friendly controls. The lack of cup holders was one of the largest operator complaints. We encourage operators to communicate to a man- Rotate Assignments ager that they are becoming fatigued. Breaks will be scheduled with no consequences to the individual. Five-minute cat naps (proven to alleviate short-term fatigue) are allowed in a vehicle, Rotating employees between plows, blowers, sweepers, and as long as that vehicle is parked in a safe location. other assignments combats fatigue by allowing the use of dif- ferent motor skills and mental processes. The use of different Another large-hub airport takes the following approach: skills and processes counters the boredom cited as a major cause of fatigue. Rotation every 4 h was the conventional The airport operates two separate teams that work six (6)-hr wisdom expressed by respondents. shifts. The shifts start and stop 0600, 1200, 1800, and 0000 hrs.