Browsing by Subject "Driving behavior"
Now showing 1 - 9 of 9
Results Per Page
Sort Options
Item Effects of Alcohol on Motorcycle Riding Skills(Minnesota Department of Transportation, 2007-12) Creaser, Janet; Ward, Nic; Rakauskas, Mick; Boer, E.; Shankwitz, Craig; Nardi, FlaviaAlcohol is known to disrupt the effect of neurotransmitters and impair various psychomotor skills. Indeed, alcohol intoxication is a significant risk factor for fatal traffic crashes, especially when riding a motorcycle. At present, there is sparse research on the impairing effects of alcohol on skills involved in motorcycle control. This study was designed to measure the effect of alcohol (up to a blood alcohol concentration of .08 grams per deciliter) on a broad set of basic riding skills. These riding skills were assessed on a test track with task scenarios based on the Motorcycle Safety Foundation’s training program. This study used a balanced incomplete block design to remove confounding artifacts (learning effects) by randomizing four BACs across three test days. Performance was characterized in terms of riding strategy used to cope with the effects of alcohol as a neurological stressor and the amount of resulting impairment with reference to specified performance standards. The analysis controlled for rider gender and age, riding skill, and drinking history. The results showed there were observable changes in motorcycle control and rider behavior in response to alcohol that are indicative of impairment. In general, intoxicated riders demonstrated longer response times and adopted larger tolerances leading to more task performance errors. Riders appeared to protect bike stability at the expense of other task performance and riders tried harder -- where possible -- to fully or partially compensate for the negative effects of alcohol. Most of the alcohol effects were evident at the per se BAC .08 g/dL level, but some of the effects were observed at the lower BAC .05. Given that this study used experienced riders performing highly practiced tasks with low to moderate levels of alcohol, the effect of alcohol on motorcycle control and rider behavior were modest except when task demand was high (offset weave), time pressure was high (hazard avoidance for near obstacles), and tolerances were constrained (circuit track). The practical significance of the findings was discussed in terms of study constraints.Item Enhanced Micro-Simulation Models for Accurate Safety Assessment of Traffic Management ITS Solutions(University of Minnesota Center for Transportation Studies, 2008-11) Xin, Wuping; Hourdos, John; Michalopoulos, PanosMuch research has been conducted in the development, implementation, and evaluation of innovative ITS technologies aiming to improve traffic operations and driving safety. Existing micro-simulation modeling only describes normative car-following behaviors devoid of weakness and risks associated with real-life everyday driving. This research aims to develop a new behavioral car-following model that is pertinent to the true nature of everyday human driving. Unlike traditional car-following models that deliberately prohibit vehicle collisions, this new model builds upon multi-disciplinary findings explicitly taking into account perceptual thresholds, judgment errors, anisotropy of reaction times and driver inattention, in order to replicate “less-than-perfect” driving behavior with all its weakness and risks. Most importantly, all parameters of this model have direct physical meaning; this ensures vehicle collisions are replicated as a result of behavioral patterns rather than simply being numerical artifacts of the model. Meanwhile, vehicle trajectories were extracted from real-life crashes collected from a freeway section of I-94WB This is by far the first data collection efforts that aim to collect vehicle trajectories from real-life crashes to aid car-following modeling. These data were employed in this study to test, calibrate and validate the model. This new model is successful in replicating these vehicle trajectories as well as crashes.Item Establishing a Repeatable Method for Presenting Nontraditional Traffic Treatments to Maximize Stakeholder Support(Minnesota Department of Transportation, 2023-08) Morris, Nichole L.; Schwieters, Katelyn R.; Craig, Curtis M.; Tian, DisiA novel infrastructure design known as the J-turn intersection reduces the risk of serious and fatal crashes at thru-STOP intersections through decreasing points of conflict at an intersection by restricting crossing movements from the minor road. Despite their demonstrated safety efficacy, J-turns have not been met with uniformly positive support. In this research, we first examine novice driver baseline attitudes and driving behaviors on J-turns using a driving simulator study. Results demonstrate that critical errors are decreased with driving exposure to the J-turn; however, attitudes toward J-turns are not improved by exposure alone. A series of studies then evaluates the efficacy of various messaging strategies and educational materials on improving attitudes toward J-turns. The findings from these studies identify that the use of both educational materials and persuasive and customized messaging strategies is an effective method for increasing acceptance of J-turns across diverse resident populations (i.e., rural, suburban, and urban) and among stakeholders in Minnesota. This work demonstrates the importance of the role of proactive educational programs and community initiatives in promoting the acceptance and buy-in toward novel roadway treatments, such as J-turns, among diverse drivers, communities, and stakeholder groups.Item A Functional Evaluation of Driving Performance for Drivers with Cataracts: Licensing Implications(Center for Transportation Studies, University of Minnesota, 1995-12) Wade, Michael; Stackhouse, Stirling P.; Melick, Ann; Tranchida, Donna; Arthur, ErikIn the design for this study we intended to use three groups of ten subjects: Younger Drivers; Older Drivers who were free of clinically significant cataracts; and drivers with advanced stage Cataracts. Data collection was completed for the first two groups and we collected data on six of the ten cataracts patients. During a greatly protracted delay due to simulator problems, Dr Melick completed her training and moved from Minnesota. We were unable to secure more cataract patients as subjects nor could we obtain the visual function data on the six cataracts patients we had tested in the simulator. This loss of subjects and data greatly reduced the intended scope of this study. This report will be written according to the changed circumstances for this project rather the original intent of the project. The results reported here are based on statistical analyses of the same three groups of subjects but with only six subjects in the Cataract group. The data are restricted to target detection data and driving performance data. Based on this limited analysis we found, as expected, that younger subjects exhibited greater sensitivity in their ability to detect targets than older subjects who in tum were more sensitive than subjects with cataracts. We also found, again as expected, that younger subjects had a greater bias toward stating that a target was present than older subjects who needed slightly less data to state that a target was present than cataract subjects. Our initial hypothesis was that older subjects would need more time to confirm that a target was present than older drivers and that this need for more time would be further extended for subjects with cataracts. This was confirmed. However, we further expected that the increased time needed for target detection by older subjects and by subjects with cataracts would result in less attention being paid to the driving task and therefore, a degradation of driving performance. This prediction was partially confirmed by the data for response time to the onset of simulated brake lights. Older subjects were significantly slower than younger subjects but while cataract subjects were slower than younger subjects, the difference was not significant. Older subjects had slower response times than Cataract subjects but again, this difference was not significant. For both the steering data (keeping the car centered in the lane) as well as for the speed maintenance data there were not significant differences among groups.Item Guidelines for safer pedestrian crossings: Understanding the factors that positively influence vehicle yielding to pedestrians at unsignalized intersections(Minnesota Department of Transportation, 2023-06) Stern, Raphael; Li, TianyiMany factors influence an individual driver's decision to yield or not yield to individual pedestrians attempting to cross the road at an unsignalized crossing. This study collects observational data from more than 3,300 crossing events at 18 intersections in Minnesota to further our understanding of what factors positively influence driver yielding. Using the collected data, a statistical analysis was conducted to identify features that most strongly correlate with driver yielding. Event specific features such as speed were found to greatly influence yielding, with vehicles traveling at a speed of greater than 25 mph significantly less likely to yield to pedestrians than vehicles traveling at speeds lower than 25 mph. Site-specific features such as the presence of signs indicating a crossing were also strongly correlated with driver yielding. The results provide indication of which features of unsignalized crossings correlate with higher driver yielding rates. These findings can be used to guide policy and design at sites where a high driver yielding rate is desirable.Item Multi-city study of an engineering and outreach program to increase driver yielding at signalized and unsignalized crosswalks(Minnesota Department of Transportation, 2023-03) Morris, Nichole L.; Craig, Curtis M.; Drahos, Bradley; Tian, Disi; Van Houten, Ron; Mabry, Marshall; Kessler, WilliamPedestrian deaths are at a 30-year high nationally, accounting for 16% of total deaths in 2018 and far exceeding the previous decade of 12%, a trend mirrored in Minnesota. Previous research found an increase in local and citywide yielding at unsignalized crosswalks following an engineering and high-visibility enforcement program in Saint Paul, Minnesota. This study examined a modified engineering-focused (i.e., without enforcement) program expanded to both unsignalized and signalized intersections across the Twin Cities. The six-month study found modest improvements in yielding from baseline to treatment end (48.1% to 65.5% in Saint Paul and 19.8% to 38.8% in Minneapolis) at unsignalized engineering treatment sites but no improvements at generalization sites. No significant improvements in left- or right-turning yielding by drivers in Saint Paul were found at treated signalized intersections, but given that yielding was significantly worse at generalization sites over time, there may be some evidence that treatments mitigated performance declines among Saint Paul drivers during the study period. Yielding improvements at signalized treatment sites were more pronounced for only right-turning drivers in Minneapolis, but generalization sites showed no improvement or even worsened over time. Overall, study results suggested no shift in driving culture in either city, as found with the previous study using police enforcement, but found some evidence of local, site-specific changes in driver yielding behavior at treatment locations.Item Rural and Urban Safety Cultures: Human-Centered Interventions Toward Zero Deaths in Rural Minnesota(Minnesota Department of Transportation, 2007-11) Rakauskas, Michael; Ward, Nicholas; Gerberich, Susan; Alexander, BruceThe total 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. We first conducted a survey of self-reported driver behavior and traffic safety attitudes. The analysis of this survey examined differences between rural and urban drivers in terms of risk taking and attitudes toward safety interventions proposed as part of the Minnesota Comprehensive Highway Safety Plan. The results suggest that rural drivers engage in riskier behavior such as seatbelt noncompliance and DUI because they have lower perceptions of the risks associated with such behaviors. Moreover, rural drivers perceive lower value in government-sponsored traffic safety interventions than their urban counterparts. We then measured driver behavior from a driving simulator comparing the driving behavior of rural and urban drivers during traffic scenarios that embodied common crash factors (distraction, speeding, car following, intersections). The results suggest that the rural environment may encourage less safe driving. This study provides policy suggestions for developing safety interventions that are designed for the psychosocial factors that define the rural culture.Item Simulation Validation: Evaluating Driver Performance In Simulation and the Real World(Minnesota Department of Transportation, 1998-07) Wade, Michael G.; Hammond, CurtisSimulation offers a cost-effective way to conduct research on collision avoidance and accident prevention. To be effective, simulated performance must be a valid measure of real world performance. This project sought to validate real world driving performance based on the performance of individuals driving in simulation. The study presents performance data on 14 male and 12 female volunteer subjects who drove a route adjacent to the University of Minnesota campus and then performed in a similar computer-generated driving route. Generally, subjects reported the simulated driving test comfortable and realistic; performance and characteristics of driving in the simulator closely paralleled the real world; the qualitative pattern of driving was similar; and errors and the control parameters of driving performance suggested acceptable reliability between both driving worlds. Researchers concluded that the simulator performed reliably and provided a valid set of performance data that could be used to better understand driving behavior, especially as it related to accident prevention and collision avoidance.Item User-centered Smart Traffic Sign Development Study(Minnesota Department of Transportation, 2023-06) Morris, Nichole L.; Rajamani, Rajesh; Drahos, Bradley A.; Xie, Zhenming; Alexander, Lee; Kessler, WilliamFlaggers protect workers by providing temporary traffic control and maintaining traffic flow through a work zone. They are often the first line of defense to stop distracted, inattentive, or aggressive motorists from intruding into the work area. This project aims to develop an automated intrusion detection system to alert drivers who are unsafely approaching or entering a flagger-controlled work zone. A human factors user needs assessment found maintenance workers preferred a modified traffic signal to feature the alert system due to flagger risks of being in the roadway and drivers failing to stop and remain stopped when presented with the STOP side of the flagger sign. A modified traffic signal that could be operated using a handheld remote was developed. The low-cost embedded electronics on the traffic signal enabled it to track trajectories of nearby vehicles, detect potential intrusions, and trigger audio-visual warnings to alert the intruding driver. Usability testing in a simulated driving test found poor expectancies and stopping rates of the traffic signal-based alarm system compared to a traditional flagger but did demonstrate evidence that drivers may be less likely to stop and remain stopped with the flagger STOP sign than the red ball indicator of the traffic signal. Furthermore, some drivers corrected their initial stopping error after triggering the auditory alarm of the traffic signal. A follow up test found improved performance with the alert system incorporated into an audiovisual enhanced STOP/SLOW flagger paddle. Testing of the developed sensor system found the system capable of simultaneous multivehicle tracking (including estimation of vehicle position, velocity, and heading) with a range of up to 60 meters and angular azimuth range of 120 degrees and correctly detecting all test intruding vehicles.