1999 From: Human Factors and Ergonomics Society
Improving Traffic Safety From The Local/Short-Haul Trucker's PerspectiveFrom Proceedings Of The Human Factors And Ergonomics Society 42nd Annual Meeting, October 5-9, 1998. SAFETY ISSUES IN LOCAL/SHORT HAUL TRUCKING: THE DRIVERS' PERSPECTIVE Richard J. Hanowski, Walter W. Wierwille, Andrew W. Gellatly, Ronald R. Knipling, and Robert Carroll ABSTRACT Focus groups were conducted to gain an understanding, from the local/short haul (L/SH) drivers' perspective, of the general safety concerns related to L/SH trucking and, specifically, the degree to which fatigue plays a role. Eleven focus groups were held in eight cities, across five states. Eighty-t~vo L/SH drivers participated. Much of the focus group activity involved discussions of critical incidents that drivers had either learned about or had personally experienced. One of the purposes of this discussion was to generate a list of causal factors that would highlight safety-critical issues in the L/SH industry. Across all sessions, the top five critical issues/causal factors, ranked in terms of importance, were: (1) Problems Caused by Drivers of Light Vehicles, (2) Stress Due to Time Pressure, (3) Inattention, (4) Problems Caused by Roadway/Dock Design, and (5) Fatigue. These findings are being incorporated into the experimental design of a follow-up study where L/SH driving data will be collected in situ. INTRODUCTION The 1992 version of the U.S. Department of Commerce's Truck Inventory and Use Survey (1994) provides definitions for the trucking industry based on range of operation. Range of operation refers to the type of trip (e.g., distance traveled) in which the vehicle typically operates. Local is defined as an operation with trips less than 50 miles from the vehicle's home base. Short range consists of trips between 50 and 100 miles from the home base. Based on these two definitions, L/SH operations can be defined as those that primarily engage in trips of 100 miles or less from their home base. In addition to mileage differences between the different trucking operations, the tasks performed by drivers of the various ranges of operation also differ. For example, long- range (long-haul) drivers, who typically drive beyond 500 miles from the vehicle's home base, are primarily concerned with operating the vehicle. Contrast this with L/SH drivers who, in addition to driving, may receive the day's driving schedule, load the vehicle, get in and out of the vehicle numerous times, lift and carry packages, and perform many other tasks. Another difference between long-haul and L/SH drivers is that L/SH drivers typically begin and end their day at their home base. This allows L/SH drivers to return to their homes after their shift and sleep in their own beds at night. Contrast this with long- haul drivers who may be on the road for several days or weeks at a time, who drive and sleep at irregular times, and who may sleep in the truck's cab or sleeper-berth during off-hours. Based on the work/sleep routine of many long-haul drivers, it is not surprising that fatigue has been an issue in their industry. It might be expected that the monotony of long-haul driving, coupled with a lack of quality sleep, would lead to driver fatigue. Previous research has found this to be the case (Miller, Miller, Lapses, Walsh, and Wylie, 1997). In other driving and non-driving domains, it is well known that psychological fatigue and physical exertion may lead to inattention and a related reduction in performance. However, in the L/SH industry, the impact that psychological fatigue and physical exertion may have on driving performance is unclear. Recently, research has been directed at determining the safety- critical issues in L/SH operations. For example, Orris et al. (1997) administered a cross-sectional questionnaire to 317 package truck drivers (i.e., L/SH drivers). The results indicated that the drivers had a higher level of psychological distress as compared to the norm of the U.S. working population. That is, drivers perceived significantly more daily stressful events than the norm. The present research was aimed at further investigating the safety issues faced by L/SH drivers. The goal of the present research was to determine the impact of L/SH operations on driver fatigue, and to determine the critical L/SH issues (i.e., causal factors of critical incidents) from the drivers' perspective. To this end, a series of focus groups were conducted to investigate fatigue and other general safety issues in L/SH trucking. METHOD Overview. Between May and August of 1997, eleven focus groups were held in eight cities, across five states. The states consisted of New Jersey, North Carolina, Pennsylvania, Virginia, and Washington. The purpose of these sessions was 167; to gain an understanding, from the L/SH drivers' perspective, of the general safety concerns related to the L/SH trucking industry. Since the emphasis of this project was on investigating fatigue in L/SH trucking, a significant portion of the focus group questions was directed at answering one basic question: "What is the extent of driver fatigue in the L/SH industry?" In addition to questions pertaining to general safety issues and driver fatigue, questions were posed to drivers concerning the L/SH industry in general. The results presented here emphasize the discussions pertaining to general safety issues, although an overview of some of the fatigue related findings is provided. For a more detailed discussion of the results related to fatigue, the reader is directed to Hanowski, Wierwille, Gellatly, Dingus, Knipling, and Carroll (in press). In addition, the technical report, from which the data presented here were taken, is being made available (Hanowski, Wierwille, Gellatly, Early, & Dingus, in press). Subjects. Eighty-two L/SH drivers participated in the focus groups. The number of participants in each session ranged from five to 10. Each driver was paid $60. Sessions lasted between 2.5 and 3 hours. Seventy-six drivers were male, and six were female. The mean age of participants was 38.9 years and ranged from 24-64 years. The mean number of years of L/SH driving experience was 9.5 years, and ranged from 2 months to 40 years. The average self-reported workweek was 48.9 hours, and ranged from 20-65 hours. The mean number of miles driven per day was 162 miles, but varied markedly from 3 miles to 425 miles. A wide range of L/SH operations was represented and included the following industries: beverage, construction, gas, common carrier, and snack foods. Drivers were recruited using three methods: (1) advertisements placed in local newspapers, (2) flyers sent to L/SH companies, and (3) via direct contact with L/SH company management. Procedure. Each focus group session began with the drivers introducing themselves to the group. Afterwards, drivers provided a general description of their job and the tasks that they typically performed. Following this introduction, drivers were asked to describe critical incidents (i.e., crashes and "close calls") that they had either personally experienced or heard about. Drivers raised both driving and non- driving incidents. As part of describing the incidents, drivers were asked to indicate what they believed to be the cause(s) of the incident. After a list of causal factors had been generated, drivers were asked to rank them in order of importance (this was completed by driver consensus). Drivers were then asked to discuss fatigue-related issues/problems that they have experienced and list the causal factors involved. Again, by consensus, drivers ranked each issue in terms of importance. To avoid biasing the participants, drivers were first asked to describe critical incidents (i.e., general safety issues) and afterwards, fatigue issues. In addition to the focus group discussion, drivers were administered paper-and-pencil questionnaires that queried them on a variety of topics. Questions included those pertaining to their job (e.g., How long have you been a L/SH driver?) and to fatigue (e.g., How many hours of sleep do you get per night?). RESULTS AND DISCUSSION Data from each of the eleven focus groups were analyzed individually and collectively. Selective results from the collectively conducted analyzes are presented here. First, to gain a better understanding of what is involved in L/SH trucking, drivers were asked to list the tasks that they perform in a typical workday and indicate the percentage of time spent on each task. Figure I shows the average percentage breakdown of the L/SH truckers' day. As can be seen, participants indicated that driving constituted their primary task and accounted for, on average, approximately 40% of their day. loading/ unloading accounted for approximately 26% of their day. Miscellaneous tasks and waiting (for a variety of reasons, including waiting to load/unload) accounted for 22% and 12%, respectively. Caution must be used in interpreting these results as there were substantial differences for drivers between industries. For example, one group of drivers, who worked for a public utility company, reported spending approximately 70% of their day driving. Contrast this to a group of drivers who hauled snack foods; they reported spending about 34% of their day driving. Much of the focus group discussion was centered on safety within the L/SH industry. Drivers were asked to discuss driving and non- driving critical incidents that they had either experienced or knew about. Based on this discussion, a list of causal factors was developed and presented to the drivers. Drivers were then asked to rank the importance of each factor. The list of general safety factors is shown in Table 1, along with a brief definition and/or example of each factor. It should be noted that the terms used in this list were generated by the drivers. Table I also shows the frequency with which each issue was raised across the eleven sessions. As can be seen, across issues, this frequency varied substantially. For example, Problems Caused by Drivers of Light Vehicles (i.e., "Other Drivers") was listed as a causal factor in all eleven focus group sessions, while Weather was raised in only two sessions. The next step in the analysis was to combine the rankings from the eleven focus group sessions to determine a consensus of the top-priority safety issues from the drivers' perspective. A weighting factor was applied to each issue to account for the frequency with which it was mentioned. As such, issues that were mentioned less frequently were treated as being "less important" as compared to issues that were mentioned more frequently. Figure 2 shows the drivers' consensus rankings of the general safety issues. Because high rankings have low numerical values, the graph, in effect, has a "reverse ordinate." As can be seen, the top five issues, ranked in order of importance and weighted for frequency, were: (1) Problems Caused by Drivers of Light Vehicles, (2) Stress Due to Time Pressure, (3) Inattention, (4) Problems Caused by Roadway/Dock Design, and (5) Fatigue. The highest-ranked critical issue, and the only issue mentioned in all eleven sessions, was Problems Caused by Drivers of Light Vehicles (i.e., Other Drivers). According to focus group participants, the problems caused by these drivers stem from two sources. The first is a poor driver attitude, where light vehicle drivers are discourteous to truck drivers and show them little respect. The second source is a lack of education on the part of light vehicle drivers. As one L/SH driver noted, "four-wheelers need to be educated on how to interact with trucks." Stress Due to Time Pressure was the second highest ranked issue and was raised in all but one of the sessions. This finding of the high importance of stress echoes the results of Orris et al. (1997), who found that package drivers had significantly higher measures of psychological distress as compared to the U.S. working population. A number of comments highlighted the stressful nature of the L/SH industry. One such comment was, "[We are] always working against the clock." Inattention was the third highest-ranked issue and was mentioned in 73% of the focus group sessions. Drivers commented that they experience inattention while driving when they think ahead to their next stop/delivery. One group of drivers mentioned that they believed inattention was caused, in part, by the proliferation of roadside signs. They noted that there are too many roadside signs and, because there are so many, they are ineffective. Another factor that may result in inattention to driving is related to time stress. Drivers are often in a rush to make delivery times and, as such, may not have time to stop for rest or lunch breaks. Problems Caused by Roadway/Dock Design was the fourth highest- ranked critical issue, and was mentioned in 55% of the focus group sessions. Over the course of the eleven sessions, drivers reported several critical incidents that had been caused by poor roadway design or poor dock design. In terms of poor roadway design, drivers mentioned examples of short merge lanes, narrow roads, and closely-positioned on and off-ramps. Drivers also noted problems with loading docks, and indicated that many newer buildings had docks that were designed more for aesthetics than for function. Fatigue was the fifth highest-ranked issue, and was raised in 36% of the focus group sessions. As noted, during the focus group sessions, discussion revolved not only around general safety issues, but also around issues specific to driver fatigue. Drivers were asked to think about and describe incidents related to times when they were fatigued on the job, and to discuss how they believe fatigue impacts the L/SH industry. As in the discussion of general safety issues, drivers were asked to list and rank causal factors of on-the job fatigue. Drivers were able to generate 22 fatigue-related issues. After discussing incidents related to fatigue and generating a list of fatigue issues, the drivers were asked to provide a consensus ranking for each issue. A discussion followed and each issue was prioritized and ranked in terms of importance. The same method used for determining priority for the general safety issues, based on the initially assigned rank and the frequency with which an issue was mentioned across sessions, was implemented with the fatigue issues. Based on this approach, the top five fatigue-related issues, ranked in order of importance, were: (1) Not Enough Sleep, (2) Hard/Physical Workday, (3) Heat/No Air Conditioning, (4) Waiting to Unload, and (5) Irregular Meal Times. To examine the importance of fatigue more closely, an analysis was conducted on the drivers within the groups that listed Fatigue as an issue and within the groups that did not list it as an issue. Note that Fatigue was raised as a general safety issue in four of the eleven focus group sessions. On a questionnaire, drivers were asked about the amount of sleep they typically got each night. A distribution of the hours of sleep for the groups of drivers that did raise Fatigue as a general safety issue was compared with the groups of drivers who did not raise Fatigue as a general safety issue. The mean number of hours of sleep for drivers who did raise Fatigue as an issue was 6.1 hours, as compared to 6.7 hours for drivers who did not raise Fatigue as a general safety issue. A two sample t-test that assumed unequal variances was conducted on the two groups and proved to be significant, t[58]=2.00, p=0.03. This finding suggests that drivers who have more sleep at night are less likely to cite Fatigue as an issue during the workday. Based on the results of these focus groups, it appears that although fatigue is an issue in L/SH trucking, it is not as critical an issue as it is in long-haul trucking. In discussing the impact of fatigue, drivers provided several reasons why fatigue is not as critical in L/SH as it is in long-haul. For example, unlike long-haul drivers, L/SH drivers primarily drive during daylight hours, have work breaks that interrupt their driving, end their shift at their home base, and sleep in their own beds at night. It appears that for L/SH drivers, fatigue results from a normal day's work, as is the case for workers of non-driving professions. Unlike long-haul drivers, where the inherent nature of their job results in fatigue, the fatigue experienced by L/SH drivers seems more likely to be impacted by their personal life (such as not getting enough sleep at night). The next phase of this project involves collecting data from L/SH drivers in real-world conditions. Driving data will be collected over a one-year period from approximately 50 L/SH drivers. To our knowledge, this will be the largest in situ data collection effort of its kind with L/SH drivers. The study will entail instrumenting L/SH trucks with a variety of data collection equipment and collecting performance data from drivers as they work their routes. The data collection equipment will include video cameras that will record the driver's face and four views outside the truck. Analysis of the data will focus on three different types of events: ( I ) critical incidents, (2) backing maneuvers, and (3) lane changes. The results of this research effort will provide much needed data on a variety of safety- related issues involving L/SH drivers. DRIVER COMMENTS AND RECOMMENDATIONS Throughout the focus group, drivers were given the opportunity to describe and discuss issues that they felt were important to the L/SH industry. Listed below are highlights of several of the main issues, along with a brief paraphrased description, quotation, or near-quotation that describes the issue. The topic areas presented here are related to four of the top five general safety issues described earlier. Interested readers should refer to Hanowski, Wierwille, Gellatly, Early, and Dingus (in press) for a more extensive presentation of issues and driver comments. Private Driver Education Educating the public is the most important thing that can be done to improve L/SH safety. Drivers feel that the public does not know how to interact with trucks. An example of private drivers' not knowing how to interact with trucks was given in reference to backing accidents. Many four- wheelers (i.e., light vehicle drivers) do not know that four-way flashers mean that a truck is backing up. There is a need for public education on how to interact with trucks. Among the suggestions were airing TV ads during prime time; having a section pertaining to truck interaction on the driver's license test; driving in a truck as part of driver training; and using tax incentives to encourage companies to advertise public education messages on trucks. Stress Due to Time Pressure "(We are) always working against the clock." One group of drivers felt that the stress due to time pressure was the most important factor affecting their safety, and was the primary reason for accidents and near misses. Participants said that drivers who are "paid per load" have increased time stress. They allege that this has a negative effect on safety and "should be outlawed." Related to time stress, a scheduling plan (i.e., a plan of the delivery order) is important for drivers making multiple deliveries. Inattention In trying to be efficient, often think about their next stop while driving to it. Drivers commented that inattention is caused, in part, by the proliferation of roadside signs: there are too many road signs and, because there are so many, they are ineffective. Drivers often eat, use an in-vehicle dispatching system, or use a computer to print orders while driving. Pagers are not useful for the driver because the displays are "impossible" to read while driving. Fatigue Fatigue in L/SH operations is considered an issue of only moderate importance. Contrast this with long-haul operations where drivers drive longer distances and get tired due to time- on-task. No air conditioning (A/C) on hot days leads to fatigue; "heat is a killer." (Note that focus groups were conducted during the late spring and summer months of 1997). A/C, the radio, and good suspension help "tremendously" with fatigue. However, the drivers do not always get the same truck every day, so one day they may have A/C and the next day they may not. Fatigue occurs when drivers are delayed due to waiting to unload freight. One driver recommended that researchers look into improving the efficiency of shipping and receiving. Drivers speculated that higher hourly pay and fewer hours (e.g., 9 hours max.) might lead to fewer fatigue-related accidents. ACKNOWLEDGMENTS The research reported here was funded by the Federal Highway Administration, Office of Motor Carriers under contract DTFH61- 96-C-00105. The authors would like to thank Nancy Early of the Center for Transportation Research for reviewing the data, Jim York of the National Private Truck Council for his insights into the Local/Short Haul industry, and Dr. Tom Dingus, Director of the Center for Transportation Research, for facilitating this research. The opinions expressed in this paper are those of the authors and do not necessarily represent official positions of any government agency. REFERENCES Hanowski, R. 1., Wierwille, W. W., Gellatly, A. W., Dingus, T. A. Knipling, R. R., & Carroll, R. (in press). Drivers' Perspective on Fatigue in Local/Short Haul Trucking. In Proceedings of the 1998 SAE International Truck & Bus Meeting & Exposition. Warrendale, PA: SAE International. Hanowski, R. J., Wierwille, W. W., Gellatly, A. W., Early, N., & Dingus, T. A. (in press). Impact of local/short haul operations on driver fatigue. Task I Report: Focus group summary and analysis. Contract No. DTFH61-96-C-00105. Washington, DC: Office of Motor Carriers, Federal Highway Administration. Massie, D. L., Blower, D., & Campbell, K. L. (1997). Short-haul trucks and driver fatigue (DTFH61-C- 00038). Washington, DC: Office of Motor Carriers, Federal Highway Administration. Mitler, M. M., Miller, J. C., Lapses, J. L., Walsh, J. K., and Wylie, C. D. (September, 1997). The sleep of long-haul truck drivers. The New England Journal of Medicine, 337, (11). Orris, P., Hartman, D. E., Strauss, P., Anderson, R. J., Collins, J., Knopp, C., Xu, Y., and Melius, J. (1997). Stress among package truck drivers. American Journal of Industrial Medicine, 31: 202-210. U.S. Department of Commerce (November, 1994). Truck inventory and use survey. 1992 census of transportation. Washington, DC: U.S. Government Printing Office. Copyright © 1998 by Human Factors and Ergonomics Society.All rights reserved. For a complete copy (with tables and figures), contact Lois Smith at [email protected].
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