Browsing by Author "Creaser, Janet"

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Connected Vehicles Program: Driver Performance and Distraction Evaluation for In-vehicle Signing
(Center for Transportation Studies, University of Minnesota, 2012-03) Creaser, Janet; Manser, Michael
The Minnesota Department of Transportation (MnDOT) conducted a demonstration project as part of the Connected Vehicles Program to design, build, and test three new software applications to run on a commercially available personal navigation device (PND). The goal of this study was to examine only the in-vehicle signing (IVS) function for four zones and determine the utility and potential distraction associated with this function. The specific zones of interest that were signed on the PND were areas where speed zone changes occurred along the same roadway or for speed changes associated with construction, school and curve zones. A continuous navigation function was provided in two of the three conditions to examine the effect of navigation information alone and multiple sources of information on driving performance. Driving performance measures known to be related to distraction as well as subjective usability and workload measures were used to help identify potential distraction associated with the IVS information. The project identified some driver effects that may occur when using a commercially available navigation device with in-vehicle signing (IVS) information, such as drivers demonstrating higher speeds associated with some of the System On conditions. Overall, distraction effects were small and not consistent across all zones or conditions. The main conclusion drawn from this study was that the IVS information was considered useful by drivers and resulted in few distraction-related effects. The benefit of advance notification likely outweighs any distraction that may be associated with in-vehicle signing of these zones.
Cooperative Intersection Collision Avoidance System – Stop Sign Assist: Experiments to Validate Use of an In-Vehicle Interface Design
(Center for Transportation Studies, University of Minnesota, 2012-04) Becic, Ensar; Manser, Michael; Creaser, Janet; Donath, Max
The three studies included in the current report examine the transition from an infrastructure-based rural intersection crossing assist system to one located inside a vehicle. The primary goals of the first study, conducted in a simulator, were to examine the effect of potentially confounding factors, such as the drivers’ familiarity with the assist system and the impact of cognitive load on the drivers’ performance. Next, we examined the efficacy of several different designs of such system to determine the optimal interface design to be used for the in-vehicle system. Finally, the optimal design of the system was examined in the third study, as a field test. The results showed that the use of the system under cognitively demanding conditions did not result in any adverse consequences, which suggested that the processing of the system required minimal cognitive resources. Additionally, the results showed that the benefits of the assist system, such as reduced probability of accepting a critical gap were exhibited under the limited visibility conditions when the perceptual task of determining an appropriate crossing gap became overly demanding. The results from the field study showed that the use of the assist system resulted in improved intersection crossing performance exhibited in increased likelihood of making a complete stop at the stop sign and showed a strong trend toward a decreased probability of accepting critical gaps. Additionally, the impact of the in-vehicle CICAS-SSA was equivalent for older and younger drivers; that is, both age groups benefited from the use of the system.
Effectiveness of a Smartphone-based Driver Support System for Reducing the Frequency of Risky Driving Behaviors in Novice Teenage Drivers
(2015-07) Creaser, Janet
Teenage driver support systems employ behavioral modification functions to assist the teenage driver in adopting safer driving behaviors. This study deployed a smartphone-based Teen Driver Support System (TDSS) that provided in-vehicle notifications to newly-licensed teenage drivers as well as sent (via text message) notifications to parents about detected risky driving behaviors (e.g., speeding, excessive maneuvers, seat belt no use). The application also blocked calling, texting and other phone applications to prevent phone-related distracted driving. This study evaluated the effectiveness of in-vehicle notifications combined with parent reporting functions to in-vehicle notifications alone in reducing certain risky driving behaviors among teenagers. Driving behavior data were collected from a control group (N=92) that engaged in naturalistic driving and two intervention groups: an in-vehicle only feedback group (partial TDSS, i.e. no feedback to the parent; N=92) and an in-vehicle feedback group in which parents also received system reports (full TDSS functionality; N=90). The results indicated an overall benefit of the full TDSS with parental feedback in significantly reducing the frequency of some risky driving behaviors, such as speeding, that are correlated with novice teenage driver crashes. In-vehicle feedback alone was less effective at reducing risky driving behaviors, indicating that parental feedback is a critical component of such systems. The cellular phone blocking functions worked effectively to reduce calling and texting in both treatment groups. The outcomes of this study indicated that monitoring applications that combine feedback and forcing functions are useful at reducing risky driving behaviors in novice teenage drivers primarily when combined with parental feedback.
Effects of Alcohol on Motorcycle Riding Skills
(Minnesota Department of Transportation, 2007-12) Creaser, Janet; Ward, Nic; Rakauskas, Mick; Boer, E.; Shankwitz, Craig; Nardi, Flavia
Alcohol 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.
Evaluation of Minnesota's Operation NightCAP Program
(Minnesota Department of Transportation, 2007-08) Creaser, Janet; Aflleje, William; Nardi, Flavia
This project evaluated Minnesota Department of Public Safety's (Mn/DPS) Operation NightCAP (Concentrated Alcohol Patrol) Program. This overtime enforcement program uses saturation patrols to identify impaired drivers. The project consisted of 3 tasks: a crash data analysis, a driver survey and an officer survey. The crash analysis indicated that saturation patrols have a marginally statistically significant effect on the decrease in fatal and severe-injury alcohol-related crashes rates in Minnesota. The effect of a single saturation is small (~0.1%), indicating that many patrols would be needed to see significant decreases in alcohol-related crash rates. A survey of 5000 Minnesota drivers in 6 counties resulted in 838 completed surveys. Approximately 19% of Minnesota drivers are aware of the Program. Drivers' beliefs about impaired driving influenced their perception of alcohol-enforcement programs and their choices to drive after drinking. Fourteen Program Coordinators and 86 law enforcement officers from the Program also responded to a survey and shared their perceptions about the Program's effectiveness. Main conclusions drawn from the surveys were that saturation patrols are not highly visible to the public and the current Program advertising is not very effective in communities where it is active. Main recommendations are to improve patrol visibility and associated advertising.
Intersection Decision Support: An Overview
(Minnesota Department of Transportation, 2007-09) Donath, Max; Shankwitz, Craig; Ward, Nic; Creaser, Janet
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. This report summarizes the results of the rural IDS system.
Sign Comprehension, Considering Rotation and Location, Using Random Gap Simulation for a Cooperative Intersection Collision Avoidance System – Stop Sign Assist: CICAS-SSA Report #4
(2010-08) Creaser, Janet; Manser, Michael; Rakauskas, Michael; Donath, Max
Crashes at rural thru-stop intersections arise primarily from a driver attempting to cross or enter the mainline traffic stream after failing to recognize an unsafe gap condition. Because the primary cause of these crashes is not failure to stop, but failure to recognize an unsafe condition, the US DOT FHWA, MnDOT, and the University of Minnesota ITS Institute undertook the CICAS-SSA program. CICAS-SSA uses roadside radar sensors, a computer processor and algorithms to determine unsafe conditions, and an active LED icon based sign to provide timely alerts and warnings which are designed to reduce the frequency of crashes at rural expressway intersections. The primary goal of this portion of the overall effort was to evaluate several candidate CICAS-SSA concepts in order to identify a single sign that may provide the greatest utility in terms of driver performance and usability at a real-world rural intersection. A secondary goal of the work was to determine the ideal physical characteristics (i.e., location and rotation of a sign relative to drivers) of the candidate CICAS-SSA at a test intersection to maximize comprehension (and subsequent use) of the sign. This report summarizes the results of the work.
A Simulator-Based Evaluation of Smart Infrastructure Concepts for Intersection Decision Support for Rural Thru-STOP Intersections
(Minnesota Department of Transportation, 2007-08) Creaser, Janet; Rakauskas, Mick; Ward, Nic; Laberge, Jason
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.
Teen Driver Support System (TDSS) Field Operational Test
(Center for Transportation Studies, University of Minnesota, 2015-11) Creaser, Janet; Morris, Nichole L.; Edwards, Christopher; Manser, Michael; Cooper, Jennifer; Swanson, Brandy; Donath, Max
Although teen drivers make up a small percentage of the U.S. driving population, they are at an especially high risk of being involved in a crash. Factors that contribute to teen drivers’ risk include their lack of experience and their tendency to engage in unsafe behaviors such as speeding, driving aggressively, or using a cell phone while behind the wheel. To help teen drivers stay safe on the road, we developed the Teen Driver Support System (TDSS), a smartphonebased system that provides real-time, in-vehicle feedback to teens about their risky behaviors—and reports the behaviors to parents via text message if teens don’t heed the system’s warnings. The TDSS provides geographically specific, realtime feedback to a teen driver at the time unsafe driving behavior occurs so that behaviors can be immediately corrected. This report documents a 12-month field operational test of the system involving 300 newly licensed teens driving on Minnesota roads. The test included a control group that received no feedback, a treatment group that received only TDSS in-vehicle feedback, and a second treatment group that received both TDSS in-vehicle and TDSS parental notifications. Research results indicate an overall safety benefit of TDSS, demonstrating that in-vehicle monitoring and driver alerts, coupled with parental notifications, is a meaningful intervention to reduce the frequency of risky driving behaviors that are correlated with novice teen driver crashes. In particular, the system was shown to be an effective strategy for reducing excessive speeds when used with parental feedback and potentially even without parental involvement.
Usability Evaluation of a Smart Phone-based Teen Driver Support System (TDSS)
(Minnesota Department of Transportation Research Services Section, 2011-05) Creaser, Janet; Gorjestani, Alec; Manser, Michael; Donath, Max
Motor vehicle crashes are the leading cause of teen fatalities. A Teen Driver Support System (TDSS) was developed by the ITS Institute that can allow parents to accurately monitor their teen's driving behavior in relation to known risk factors and Graduated Driver Licensing (GDL) provisions. The TDSS, based on a teen's smart phone, provides real-time, contextual in-vehicle feedback to the teen about his or her driving behavior and helps parents monitor certain known risk factors. The system does not allow incoming or outgoing phone calls (except 911) or texting while driving. Feedback to the teen driver includes visual and auditory warnings about speeding, excessive maneuvers (e.g., hard braking, cornering), and stop sign violations. The TDSS prototype also monitors seat belt use and detects the presence of passengers (e.g., based on GDL provisions), two known factors that increase the risk of fatalities among teen drivers. The TDSS can also be programmed to monitor driving during the GDL curfew or a curfew set by parents. A usability review of the prototype TDSS using 30 parent-teen dyads from Washington Country, MN, found that teens and parents held favorable opinions about most of the TDSS functions. Teens and parents both felt that use of the system early in licensure may result in the adoption of safer driving habits even after the system is removed from the vehicle. Several recommendations to improve the system’s usability are made based on the results.
Validation Study – On-Road Evaluation of the Cooperative Intersection Collision Avoidance System – Stop Sign Assist Sign: CICAS-SSA Report #5
(2010-08) Rakauskas, Michael; Creaser, Janet; Manser, Michael; Graving, Justin; Donath, Max
The CICAS-SSA sign is a roadside driver support system that is intended to improve gap rejection at rural stopcontrolled intersections. The CICAS-SSA system tracks vehicle locations on a major roadway and then displays a message to a driver on the minor road via an active LED icon-based sign. The basis of this sign is a “Divided Highway” sign that is commonly presented in traffic environments. Overlaid on the roadways of the sign are yellow or red icons that represent approaching vehicles that are at a distance at which the driver on the minor road should proceed with caution or at a distance that is considered unsafe to enter the intersection. Previous research conducted in a driving simulation environment indicated potentially beneficial changes in driver decision-making relative to approaching vehicle gap sizes and indicated that drivers perceive the system as being both useful and satisfying. While simulation-based evaluations provide a wealth of useful information, their ability to replicate the full array of behavioral, cognitive, and perceptual elements of a driving environment do have some limitations. It is because of these limitations that it is useful to confirm simulation-based findings in a real-world environment. The primary goal of the current work was to evaluate the candidate CICAS-SSA sign in a real-world setting to confirm previously identified benefits and identify any unintended consequences of sign usage. This goal was accomplished through a validation field test performed at the intersection of US Highway 52 and County Road 9 in Southern Minnesota. The findings of the work are summarized in this report.

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Browsing by Author "Creaser, Janet"