Jeffrey S. Hickman

A safety self-management intervention for mining operations.

PROBLEM This quasi-experimental field study examined the efficacy of a safety self-management process to increase safety-related work practices in mining operations. METHODS After a 7-week baseline, 15 miners participated in a safety self-management training and education presentation. The participants in a prebehavior condition (n=8) recorded their intentions to engage in specific percentages of safety-related work behaviors before starting their shift for the day. In contrast, participants in a postbehavior condition (n=7) recorded their percentages of safety-related work behaviors after their shift for the day. RESULTS During withdrawal (4 weeks), the miners did not complete any self-monitoring forms. Based on 10,905 behavioral observations, safety self-management was effective at increasing the frequency of safety-related behavior (p<.05). For the prebehavior condition, the mean percent safe score across three target behaviors increased 34.8% during intervention. Similarly, in the postbehavior condition, the mean percent safe score across three target behaviors increased 40.1% during intervention. IMPACT ON INDUSTRY The results suggest that employees who work in relative isolation or have little oversight, compared to traditional industrial workers, may benefit from a process by which they can systematically observe themselves.

Self-Management to Increase Safe Driving Among Short-Haul Truck Drivers

Abstract The relative impact of a self-management for safety (SMS) process was evaluated at two short-haul trucking terminals. Participants in the Pre-Behavior group (n= 21) recorded their intentions to engage in specific safe versus at-risk driving behaviors before leaving the terminal (i.e., before making any of their deliveries for the day), whereas participants in the Post-Behavior group (n = 12) recorded their actual safe versus at-risk driving behaviors after returning to the terminal (i.e., after making all their deliveries for the day). Each participant drove a truck equipped with an on-board computer-monitoring device that recorded two driving behaviors, traveling > 63 mph (overspeed) and stopping or braking ≥ 7 mph/sec (extreme braking). During the SMS intervention, participants in the Pre-Behavior group reduced their mean percentage of time overspeeding by 30.4%, and their mean frequency of extreme braking incidents by 63.9%. Similarly, during the SMS intervention, the Post-Behavior group reduced their mean percentage of overspeeding and their mean frequency of extreme braking incidents by 19.3% and 49.4%, respectively.

An Assessment of Commercial Motor Vehicle Driver Distraction Using Naturalistic Driving Data

Objective: This study analyzed naturalistic driving data from commercial trucks (3-axle and tractor-trailer/tanker) and buses (transit and motorcoach) during a 3-month period. Methods: The data set contained 183 commercial truck and bus fleets comprising 13,306 vehicles and included 1085 crashes, 8375 near crashes, 30,661 crash-relevant conflicts, and 211,171 baseline events. Study results documented the prevalence of tertiary tasks and the risks associated with performing these tasks while driving. Results: Results indicated the odds of involvement in a safety-critical event differed as a function of performing different cell phone–related subtasks while driving. Although the odds ratio for talking/listening on a cell phone while driving was found to not significantly increase the likelihood of involvement in a safety-critical event, other cell phone subtasks (e.g., texting, dialing, reaching) were found to significantly increase the odds of involvement in a safety-critical event. Conclusions: The results suggest that cell phone use while driving should not be considered a simple dichotomous task (yes/no). Consideration should instead be made for a set of discrete cell phone subtasks that are each associated with varying levels of risk. Several hypotheses are presented to explain why cell phone use while driving was found to not increase the likelihood of involvement in a safety-critical event.

Evaluating the 2003 revised hours-of-service regulations for truck drivers: The impact of time-on-task on critical incident risk

On January 4th, 2004, the Federal Motor Carrier Safety Administration implemented a revised set of regulations concerning the hours-of-service (HOS) of commercial motor vehicle (CMV) drivers. One central component of the revised HOS regulations was a one-hour increase in allowable driving time, from 10 to 11h. The current study evaluated the impact of the additional driving-hour on critical incident risk. Data from a naturalistic truck driving study, which resulted in over 2 million driving miles of continuously collected data, were analyzed. Driving hour bins (hours 1 through 11) were created and the frequency of critical incidents for each hour, and trips (opportunities) per each hour, were identified. A relative frequency was then calculated (critical incidents divided by opportunities) for each hour and odds ratios were determined. Analyses found an elevated risk in the 1st driving-hour, but no consistent significant difference between hours 2 through 11. Analyses on time-of-day, where incident rates were calculated for each of the 24h in the day, were also conducted. The results found a strong positive correlation to national traffic density data. As an impact on U.S. national transportation policy, the results of this study do not support the hypothesis that there is an increased risk resulting from CMV drivers driving in the 11th driving-hour as compared to the 10th driving-hour, or any hour.

Efficacy of roll stability control and lane departure warning systems using carrier-collected data.

INTRODUCTION Large truck crashes have significantly declined over the last 10 years, likely due, in part, to the increased use of onboard safety systems (OSS). Unfortunately, historically there is a paucity of data on the real-world efficacy of these devices in large trucks. The purpose of this study was to evaluate the two OSSs, lane departure warning (LDW) and roll stability control (RSC), using data collected from motor carriers. METHOD A retrospective cohort approach was used to assess the safety benefits of these OSSs installed on Class 7 and 8 trucks as they operated during normal revenue-producing deliveries. Data were collected from 14 carriers representing small, medium, and large carriers hauling a variety of commodities. The data consisted of a total of 88,112 crash records and 151,624 truck-years that traveled 13 billionmiles over the observation period. RESULTS The non-LDW cohort had an LDW-related crash rate that was 1.917 times higher than the LDW cohort (p=0.001), and the non-RSC cohort had an RSC-related crash rate that was 1.555 times higher than the RSC cohort (p<0.001). CONCLUSIONS The results across analyses indicated a strong, positive safety benefit for LDW and RSC under real-world conditions. PRACTICAL APPLICATIONS The results support the use of LDW and RSC in reducing the crash types associated with each OSS.

Safety Impacts of Speed Limiter Device Installations on Commercial Trucks and Buses

This synthesis examines and summarizes literature and industry information relating to speed limiters; exploring questions concerning measurable safety impacts, metrics, and degree of benefit, if any. Speed limiters, also described as speed governors, are devices that interact with a truck engine to only permit the attainment of a pre-programmed speed. The purpose is to synthesize data, research, and analyses performed to date in terms of both methodologies employed to assess speed limiters and the actual results, which may be used to guide policy development in North America. The scope of the project encompassed an assessment of the safety efficacy of speed limiters, for commercial motor vehicles in Australia and Europe, as well as in North America and, in addition, for commercial vehicle operations, surveyed truck and intercity and charter bus carriers, that have experience in using speed limiters regarding perceived benefits and/or drawbacks. It is noted that, although this synthesis provides a general understanding of speed limiter use in commercial motor vehicle operations, it does not provide a methodological comparison of before-and-after results applied uniformly across predefined truck and bus fleet operations. An approach to an in-depth empirical study that would gather data from the commercial truck and bus industry with regard to the safety effectiveness of speed limiters is suggested. A primary (small population convenience) survey that targeted fleet safety managers within specific companies, representing roughly 400 truck and motor coach fleets plus other industry stakeholders, was administered to obtain additional insight from actual users as to speed limiter usage levels and perceived benefits and drawbacks of speed limiters. Fifteen hundred synthesis surveys were distributed and 103 responses were received, for a response rate of approximately 7%.

Safety Benefits of Speed Limiters in Commercial Motor Vehicles Using Carrier-Collected Crash Data

The purpose of this study was to identify the safety impacts of speed limiters in commercial truck fleets. The primary safety analysis was a focus on the reduction in truck crashes that could have been avoided or mitigated with an active speed limiter installed on the truck. This was the first study to use actual truck crash data collected directly from commercial truck fleets, representing a wide array of crashes. The study included data from 20 commercial truck fleets, including approximately 138,000 truck-years and more than 15,000 truck crashes, as they operated under real-world, revenue-producing deliveries. The findings showed strong positive benefits for speed limiters. Results indicated that trucks equipped without speed limiters had a significantly higher speed limiter-relevant crash rate (approximately 200%) compared to trucks with speed limiters. The cost of the technology is negligible and would not be expected to be cost-prohibitive for commercial truck fleets/owners. The current study went further than any prior research conducted in this domain and provides important data on the efficacy of speed limiters in reducing speed limiter-relevant crashes.

An observational study of the safety benefits of electronic logging devices using carrier-collected data

ABSTRACT Objective: Fatigue has been shown to be a contributing factor in many large truck crashes. Long duty periods, irregular work schedules, and poor sleeping environments make fatigue a noteworthy concern in trucking operations. One way to limit fatigued driving is through prescriptive hours-of-service (HOS) regulations. This duty status information is typically recorded in written logs; however, more trucking companies are moving toward electronic HOS recorders. These devices were first marketed as productivity tools; however, more recently they have been touted for their safety benefits in reducing fatigued truck drivers (because falsifying electronic logs is difficult). Methods: The purpose of the current study was to assess the benefits of electronic logging devices (ELDs) on safety and HOS violations in trucks as they operated during normal revenue service. Data on crashes, HOS violations, mileage, and onboard safety systems were obtained from participating motor carriers. Although the final data sets included data from 11 carriers representing medium and large carriers (including a total of 82,943 crashes, 970 HOS violations, and 224,034 truck-years that drove a total of 15.6 billion miles), the data set in the study was skewed toward larger, for-hire carriers and may not represent the overall U.S. trucking population. Results: After controlling for calendar year, carriers in the data set, onboard safety system status, and long-haul/regional indicator, ELD-equipped trucks had a significantly lower total crash rate (11.7% reduction), preventable crash rate (5.1% reduction), driving-related HOS violation rate (53% reduction), and non-driving-related HOS violation rate (49% reduction) than trucks not equipped with ELDs. Conclusion: The results show a clear safety benefit, in terms of crash and HOS violation reductions, for trucks equipped with ELDs.

Drug Use and Involvement in a Safety-Critical Event: Pilot Study Using Naturalistic Truck Data

This study used the Naturalistic Truck Driving Study data set to test the feasibility of applying naturalistic data to evaluation of the relationship between prescription (Rx) and over-the-counter (OTC) drug use and involvement in a safety-critical event (SCE). The risk of drug use was calculated by comparing SCEs and baseline epochs that occurred within a drugs half-life with SCEs and baseline epochs that did not occur within a drugs half-life (for the same half-life period). This research found that nearly 97% of commercial motor vehicle drivers used an OTC drug at least once (mostly caffeine), and 25% used at least one Rx drug. Furthermore, Rx and noncaffeine OTC drug use was not associated with an increased or decreased risk of involvement in an SCE. As caffeine was the only drug classification used multiple times by many drivers, this odds ratio analysis was the only analysis performed. Caffeine use while driving was found to be associated with a decreased risk of SCE involvement in all seven half-lives (half-life odds ratios ranging from 0.44 to 0.66). This project illustrated the feasibility of using a naturalistic driving approach to assess the risk associated with Rx and OTC drug use while driving. It is possible that analyses for specific medications could be performed with a sufficiently large sample of drivers who used each classification of drug.

Challenges in Hazard Detection for Commercial Motor Vehicle Drivers: A Driving Simulator Training Study

There are few research studies that have assessed the hazard detection (HD) challenges of experienced, skilled drivers. This paper presents the pilot study results of an HD training program, Commercial Driver Assessment and Training System (CDATS), developed for commercial motor vehicle (CMV) drivers. The training involved simulation-based videos that highlight potential vehicle, pedestrian, and visually hidden hazards during unprotected intersection maneuvers: left-turn, right-turn, and straight-thru. Low-fidelity driving simulations were designed to reinforce video lessons and increase the expectation and detection of potential hazards. Training efficacy was assessed using a driving simulator HD task presented to short-haul CMV drivers (N = 16) at pre-/post-assignment to CDATS training or a control condition. Results suggested that CMV drivers had highest HD task accuracy (% correct) for vehicle hazards and lowest accuracy for visually hidden hazards. Performance for pedestrian hazards was dependent on the intersection maneuver, with performance decreases for left-turn, right-turn and straight-thru intersections, respectively. Post-test results suggested overall HD improvement in the CDATS training group with no change in the control group; however, there was no significant change in relative hazard type by intersection maneuver pattern. Similar to prior research, experienced CMV drivers may also exhibit challenges in HD, particularly for visually hidden and visible pedestrian hazards, and may benefit from HD training.