Ward, Nicholas J.

The goal of this study was to develop a survey methodology for Minnesota to measure state-level traffic-safety culture with three objectives: 1. Index traffic-safety culture as a performance indicator. 2. Identify culture-based strategies to achieve safety targets. 3.Assess receptivity of social environment for planned strategies. The survey was designed around a definition of safety culture as "the socially constructed abstract system of meaning, norms, beliefs, and values." (Myers et al., 2014; Reiman & Rollenhagen, 2014) Given that the majority of cases in which driver behavior is associated with fatal crashes can be presumed to be deliberate, these cognitions determine the intention to behave in either a safe or risky manner. This definition emphasizes that cognitions - shared by a group of people - influence the behavioral choices of the individual group members. The survey was designed to be implemented using a paper instrument mailed to households in Minnesota. The sample was based on a random sample of 10,000 Minnesota household addresses selected in November 2013 to cover all Area Transportation Partnership (ATP) boundary areas. The results indicate that many aspects of Minnesota are predictive of the level of engagement in both risky and protective behaviors. Often, the misperception that risk-taking is common and accepted increased the probability that individuals would decide to engage in risky behaviors themselves. The results are used to recommend strategies to increase concern about traffic safety overall and to reduce the incidence of risky behaviors in favor of safer choices.

The purpose of this project was to explore beliefs and attitudes about risky driving behavior and traffic safety interventions between urban and rural drivers as a function of age. This was accomplished by conducting focus groups and surveys in rural and urban areas with teens and seniors. Results indicated that traffic safety policy for teens should focus on distraction and sensory-motor functioning amongst seniors. In terms of traffic safety policy for rural areas, attention should be given to interventions promoting seatbelt compliance. Relative to traffic safety interventions, teens felt GDL helped them become better drivers but weren't convinced GDL had made them better/safer. Teen felt smart technology could have positive effects on safety, but an acceptable program based on this technology needs to balance factors such as cost, robustness, and limitations on driving. Seniors were receptive to mandatory testing but felt it must be flexible, objectively administered, and based on criteria other than age. Rural seniors were concerned about alternative mobility programs for those drivers that fail the proposed test. Relative to these alternative programs, seniors' acceptance was related to the perceived accessibility to a safe and affordable program that is sufficiently versatile to accommodate a range of transportation needs.

As a logical and necessary extension of previous research (Rakauskas, et al., 2005), this study aims to assess the risk of cell phone use for traveler information applications; namely while using Minnesota's 511 interactive voice response (IVR) menu. First, detailed usage, utility, and usability evaluations of the MN511 were conducted. The goal of this design was to help harmonize the transfer of knowledge between access methods while also easing implementation concerns for the MN511 developers. Next, a simulated driving experiment was conducted with the goal of seeing if using an IVR menu leads to more risky driving behavior compared to driving while not accessing a menu. It also allowed us to see if changing the MN511 menu might affect driver performance. While using both phone menus, drivers seemed to compensate for the additional mental workload by delaying their reactions until they felt comfortable taking action. There were no differences between the two menu types for the majority of driving performance measures. This study addresses issues with the 511 IVR menus that were identified during this study and presents recommendations for future development.

The number of annual traffic fatalities and the rate of fatalities per vehicle mile traveled are considerably higher in rural areas compared to urban areas. This project aimed to be one of the first studies to systematically explore the potential contribution of rural driver attitudes and behavior that may be a causal factor of these trends.

Report #6 in the series: Developing Intersection Decision Support Solutions. Minnesota joined with California, Virginia, and the FHWA in a pooled fund consortium (the Infrastructure Consortium) dedicated to improving intersection safety. The Minnesota team's objective is to develop effective strategies to mitigate high crash rates at rural intersections. Rural Intersection Decision Support (IDS) focuses on enhancing the driver's ability to successfully negotiate rural intersections. The system uses sensing and communication technology to identify safe gaps in traffic on a high-speed rural expressway and communicate this information to drivers waiting to enter the intersection from a minor intersecting road. The goal of this system is to improve safety without introducing traffic signals, which on high-speed rural roads often lead to an increase in rear-end crashes. The Rural IDS research program achieved four main research results: an analysis of rural expressway intersections, including development of a technique to identify those with higher-than-expected crash rates; development of a statistical model that can be used to estimate the benefits of deploying IDS at a specific rural intersection; design and implementation of a rural intersection surveillance and data acquisition system capable of quantifying the behavior of drivers; and a task analysis, design study, and simulator-based evaluation of Driver Infrastructure Interface (DII) concepts for communicating relevant information to stopped drivers.

Report #4 in the series: Developing Intersection Decision Support Solutions. This report describes the human factors basis for an intersection decision support (IDS) system intended to improve the safety of rural intersections in Minnesota's Interregional Corridors (IRCs). The purpose of the human factors effort is to understand the task of rural intersection negotiation, identify high-risk user groups, describe the human factors that contribute to intersection accidents, and determine what conceptual types of information to present in the IDS display to improve driver performance and safety. Consistent with the original infrastructure consortium proposal, this report emphasizes gaps, older drivers, and rural thru-STOP intersections (Donath & Shankwitz, 2001). This is because older drivers have a high accident risk at rural thru-STOP intersections and problems with gap detection, perception, and acceptance are contributing factors. A task analysis of rural thru-STOP negotiation was used to define the informational requirements for an IDS system for assisting with gap detection, perception and judgment. An abstraction hierarchy defined the operator (driver) constraints relevant to an infrastructure-based IDS system. Four design concepts were constructed and tested in a driving simulator with older (55+) and younger (20-40) drivers in day and night driving conditions. Two designs resulted in the largest mean gap acceptance across groups when compared to baseline. The two design concepts also were most favored by the majority of participants.

The crash risk associated with cell phone use while driving is a contentious issue. Many states are introducing Advanced Traveler Information Systems (ATIS) that may be accessed with cell phones while driving (e.g. 511 Traveler Information Services). In these contexts, there is a need for relevant research to determine the risk of cell phone use. This study compared driver performance while conversing on a hands-free cell phone to conditions of operating common in-vehicle controls (e.g., radio, fan, air conditioning) and alcohol intoxication (BAC 0.08). In addition, the study examined the combined effects of being distracted and being intoxicated given that there may be a higher risk of a crash if the driver engages in a combination of risk factors. During simulated traffic scenarios, resource allocation was assessed through behavioral measures and an event-related potential (ERP) novelty oddball paradigm. The results indicated that during a car following scenario, drivers engaged in the conversations or completing in-vehicle tasks were more impaired than drivers that were not involved in any distraction task. Indeed, both the cell phone and in-vehicle sources of distraction were generally more impairing than intoxication at the legal limit. These results will be used in a follow up study in order to compare the effects on attention of driving and using 511 to distraction from these tested distractions.

This track test supplements an attempted field operational test (Rakauskas et al., 2003) which did not provide enough experience using the Driver Assistive System (DAS) during low-visibility conditions to make reasonable conclusions on driving performance. This study aimed to determine the usefulness of the DAS in the context of simulated low-visibility conditions. Drivers drove in clear, low-visibility, and DAS-assisted low-visibility conditions. Driving performance measures were taken while driving and drivers were asked workload, trust, and subjective response questions after each condition and post-experiment. The DAS enabled drivers to maintain consistent lane position and to make fewer steering corrections than while driving the low-visibility condition. Using the DAS during low-visibility conditions did not change speed performance and aided the driver by providing additional information about the road. More mental effort was reported while assisted by the DAS than while driving unassisted in the low-visibility condition. This was expected since drivers were presented with and were expected to mentally process more information while assisted. Many of the trends found were consistent with our previous thoughts on how the DAS would perform. However, due to the small number of drivers tested in the FOT and track testing studies there was low power for our statistical analyses. We encourage further research with the DAS on larger numbers of drivers or in a more powerful study design. Some changes are also recommended for future versions, such as providing a warning prior to loss of GPS fix. Project study to assess the usefulness of the Driver Assistive System (DAS) in the context of driving snowplows in low-visibility conditions on a test track. The system was found to be useful; several design improvements to the system are suggested to maximize its effectiveness.

This study aimed to determine the usefulness of the Driver Assistive System (DAS) in the context of plowing roads during low-visibility conditions. Driving performance, driver workload, and system performance were to be compared in a field operational test (FOT). Geographical location of the driver's route proved to play a large part in the desirability and perceived reliability of the system, as rural drivers preferred the system due to the lack of lighting and visual guidance while driving in low-visibility conditions. Most drivers did not have problems remembering how to use the DAS, and that the system made them feel safer and more in control while driving. The haptic seat was praised for giving warnings while letting them keep their eyes on the road or performing other in-cab tasks and their ideal configuration would be to use the haptic seat and/or the HUD. Due to an uncharacteristically mild winter weather conditions, it was decided that the FOT would not provide enough experience using the DAS during low-visibility conditions to make reasonable conclusions on driving performance. Therefore, it was necessary to use an additional experimental design with a track test, which is discussed in a supplemental document (Rakauskas et al., 2003).