Janet Creaser

Effects of alcohol impairment on motorcycle riding skills

Alcohol intoxication is a significant risk factor for fatal traffic crashes; however, there is sparse research on the impairing effects of alcohol on skills involved in motorcycle control. Twenty-four male motorcycle riders between the ages of 21 and 50 were assessed on a test track with task scenarios based on the Motorcycle Safety Foundations (MSF) training program. A balanced incomplete block design was used to remove confounding artifacts (learning effects) by randomizing four BAC levels across three test days. In general, intoxicated riders demonstrated longer response times and adopted larger tolerances leading to more task performance errors. Most of the alcohol effects were evident at the per se 0.08% alcohol level, but some of the effects were observed at the lower 0.05% alcohol level. The effects of alcohol on motorcycle control and rider behavior were modest and occurred when task demand was high (offset weave), time pressure was high (hazard avoidance for near obstacles), and tolerances were constrained (circuit track). The modest effects may be due to the study design, in which experienced riders performed highly practiced, low-speed tasks; alcohol at these levels may produce larger effects with less experienced riders in more challenging situations.

Are cellular phone blocking applications effective for novice teen drivers

PROBLEM Distracted driving is a significant concern for novice teen drivers. Although cellular phone bans are applied in many jurisdictions to restrict cellular phone use, teen drivers often report making calls and texts while driving. METHOD The Minnesota Teen Driver Study incorporated cellular phone blocking functions via a software application for 182 novice teen drivers in two treatment conditions. The first condition included 92 teens who ran a driver support application on a smartphone that also blocked phone usage. The second condition included 90 teens who ran the same application with phone blocking but which also reported back to parents about monitored risky behaviors (e.g., speeding). A third control group consisting of 92 novice teen drivers had the application and phone-based software installed on the phones to record cellular phone (but not block it) use while driving. RESULTS The two treatment groups made significantly fewer calls and texts per mile driven compared to the control group. The control group data also demonstrated a higher propensity to text while driving rather than making calls. DISCUSSION Software that blocks cellular phone use (except 911) while driving can be effective at mitigating calling and texting for novice teen drivers. However, subjective data indicates that some teens were motivated to find ways around the software, as well as to use another teens phone while driving when they were unable to use theirs. PRACTICAL APPLICATIONS Cellular phone bans for calling and texting are the first step to changing behaviors associated with texting and driving, particularly among novice teen drivers. Blocking software has the additional potential to reduce impulsive calling and texting while driving among novice teen drivers who might logically know the risks, but for whom it is difficult to ignore calling or texting while driving.

A Comparison of Work Domain and Task Analysis for Identifying Information Requirements: A Case Study of Rural Intersection Decision Support Systems

Minnesota drivers are over-represented in accidents at rural intersections and many crashes are attributable to drivers accepting unsafe gaps. In this context, intersection decision support (IDS) systems are promising technologies for supporting driver decision-making. A significant activity during IDS development is to determine the information requirements to display to drivers. To be effective, an IDS system must present information that helps drivers successfully negotiate intersections. This paper compares two methods for identifying information requirements: work domain analysis (WDA) and hierarchical task analysis (HTA). Results showed that 58% of the requirements were identified by WDA, 7% by HTA, and 35% by both methods. An analysis of driver errors at intersections during the HTA activity identified that drivers can perceive gaps at intersections in different ways. This important nuance was not captured in the WDA. Therefore, both WDA and HTA are effective methods for identifying information requirements. Discussion focuses on the importance of both WDA and HTA in IDS system development.

Evaluation of driver performance and distraction during use of in-vehicle signing information

The goal of this study was to examine the in-vehicle signing (IVS) function displayed on a mobile device to determine whether drivers’ compliance with speed limits increased when IVS information was present. The study also sought to identify whether any visual distraction occurred while the IVS information was being used. Notifications of speed zone changes along a roadway, of school zones, construction zones, and curves were visually displayed on a mobile device as per project requirements. Sixty participants (balanced for gender) completed the study, which involved performing a simulated drive in one of three conditions along 24 mi of roadways. The three system-on groups represented the following information conditions: IVS plus navigation, navigation only, or IVS only. Each group also completed a baseline (system-off) condition. The driving performance results indicated that drivers complied with most speed zones whether IVS information was present or not; however, average speeds tended to be higher in the system-on conditions. Drivers in the IVS-only condition spent significantly less time looking at the in-vehicle display than drivers who were also presented with navigation information. Response time to a roadside visual detection task was significantly increased only in speed transition zones whether IVS information was present or not. This condition suggests that increased driver workload occurs during transitions to a new speed zone, particularly when drivers are required to search the environment for additional visual information (e.g., signs, pedestrians, other vehicles).

Determining effective orientation and location of decision support signs at rural intersections

Drivers face an increased crash risk when making gap acceptance decisions at high speed, unsignalized, rural intersections. The use of Stop-Sign Assist (SSA) intersection decision-support systems aims to assist drivers with these difficult decisions. This effort to identify effective placement of SSA systems will play a critical role in how the information is interpreted and utilized to successfully navigate an intersection. A driving simulator was used to present virtual representations of an intersection in Minnesota where SSA signs are planned for deployment. This study suggested which angles and locations would result in faster and more accurate comprehension of the signs. These results provide guidance for more effective comprehension, viewing, and acceptance of IDS signs at similar rural, trunk highway intersections.

Rural Stop-Controlled Intersection Decision Support Systems

Minnesota drivers are over-represented in accidents at rural stop-controlled intersections. There is also evidence that drivers in other states as well as older drivers are involved in many of these crashes. A task analysis and literature review showed that rural drivers could be getting into accidents because of problems detecting vehicles or gaps, perceiving or estimating the size of gaps, and/or judging gaps as safe. It is suggested that intersection decision support (IDS) systems present drivers with information elements that help them correctly identify and locate other vehicles and in some cases highlight (safe) gaps in approaching traffic. Several design concepts are proposed and research needs are discussed.