James Jenness

Perceptions and Experiences of Participants in a Study of In-Vehicle Monitoring of Teenage Drivers

Objectives: To assess the perceptions and experiences of participants in a study of a device that monitored teenagers’ driving. Methods: A device that continuously monitors and reports risky driving maneuvers was installed in vehicles of 84 newly licensed teenagers. Study groups varied by whether parents had access to a Web site that summarized their teenagers’ driving and by whether in-vehicle alerts provided feedback to drivers. Recruitment of subjects and problems with the device were documented. Teenagers and parents were interviewed after removal of the device. Results: Although the study was conducted in a large urban area, recruitment progressed slowly. Parents who declined to participate usually said their teenagers opposed it, or they were concerned about intruding on the privacy of their children or jeopardizing trust with them. Both parents and teenagers thought in-vehicle alerts helped teenagers drive more safely, although two thirds of teenagers tried to drown out the alerts with loud music. Parents found the Web site useful but reported fewer Web site visits over time. Most parents would prefer receiving information through summary report cards rather than through a Web site. Both parents and teenagers thought the overall system was effective in improving teenagers’ driving. Most parents said the Web site and/or device helped them talk to their teenagers about their driving. Parents thought the most effective system would be an in-vehicle alert with immediate parental notification; teenagers preferred a system allowing them to correct behavior before parental notification. Conclusions: The difficulties in recruiting families for a study of in-vehicle monitoring and feedback technology suggest that gaining broad acceptance may be challenging. Although many teenagers were annoyed by the technology, most said they drove more safely because of it. Sending report cards to parents and allowing teenagers to correct behavior before parents are notified may increase the usefulness and acceptability of monitoring systems.

A Binary Response Method to Determine the Usability of Seven In-Vehicle Fuel Economy Displays

We employed a binary response method to evaluate the usability of seven fuel economy displays. The displays were set to show various levels of fuel economy and then static images of the displays were generated. Participants were presented the images and asked to indicate if the information on the fuel economy display indicated fuel economy was greater or less than an arbitrary average fuel economy. A display that consisted of a binary metric of fuel economy and an incremental metric of acceleration best facilitated the determination of fuel economy.

Determining the Accuracy and Acceptance of Using Driver Interface Display Components and Fuel Economy Information Types

If novel displays in the vehicle are not easily understood, they may increase driver distraction and result in higher crash risk. In this way, improving the usability of in-vehicle displays may decrease crash risk. However when there are a large number of interface design options, it is difficult to quickly determine which will be the most beneficial. The goal of this evaluation was to identify fuel economy display components and information types that would have the highest potential to improve accuracy and acceptance. Participants were more accurate at identifying fuel economy level when viewing information presented on horizontal bar display components with reference points. Subjective scores suggested that a balance of instantaneous and long-term information types was associated with greater interface acceptance. Results of this rapid assessment show the utility of supplementing objective accuracy measures with subjective acceptance metrics when considering multiple user interface designs.

Perception of Approaching Motorcycles by Distracted Drivers May Depend on Auxiliary Lighting Treatments: A Field Experiment

A field experiment was conducted in daylight with 32 participants to determine whether left turning drivers’ gap acceptance in front of approaching motorcycles depends on the motorcycle’s forward lighting treatment. Five experimental lighting treatments including a modulated high beam headlamp, or the low beam headlamp plus pairs of low-mounted auxiliary lamps, high-mounted auxiliary lamps, both high- and low-mounted auxiliary lamps, or low-mounted LED lamps were compared to a baseline treatment with only the low beam headlamp illuminated. Participants viewed the approaching traffic stream (including the motorcycle) on an active roadway and indicated when it would be safe (and not safe) to initiate a left turn across the opposing lanes. Participants also shared their attention with a secondary visual distraction task that took their eyes off the forward roadway. Participants did not know that the purpose of the study was to measure their responses to approaching motorcycles. Based on participants’ indications of the last safe moment to turn, the mean temporal safety margin provided to the approaching motorcycle did not differ significantly between any of the experimental lighting treatments and the baseline treatment. However, having either low-mounted auxiliary lamps or modulated high beam lamps on the motorcycle significantly reduced the probability of obtaining a potentially unsafe short safety margin as compared to the baseline lighting treatment. Overall, the results suggest that enhancing the frontal conspicuity of motorcycles with lighting treatments beyond an illuminated low beam headlamp may be an effective countermeasure for daytime crashes involving right-of-way violations.

Safe Driving in the Multi-Tasking Generation

The objective of this discussion panel is to approach the teen driver distraction issue from the driver life-style point of view. As revealed in various focus groups and surveys, multi-tasking is “just what they do,” and what they have grown up doing. How (if at all) is the current generation of young drivers distinct in terms of multi-tasking? What are the implications and how might we deal with this? The approach here is to provide a multi-disciplinary panel that offers a range of expertise and perspectives on studying these issues. Each of five panelists will present a brief perspective of the problem from the point of view of their expertise. This will be followed by an open discussion period.

Visibility and Conspicuity of Detectable Warnings for Pedestrians with Visual Impairments

Detectable warnings are standardized tactile walking surfaces located at the end of curb ramps and train platforms to identify the potential hazard. A study was conducted to determine which detectable warning colors and patterns are visually detectable and conspicuous to pedestrians with visual impairments and to provide recommendations related to color, pattern, and contrast of detectable warnings for placement on sidewalks. Fifty individuals with low vision viewed each of 13 detectable warnings individually on four different types of simulated sidewalk. The set of detectable warnings included both solid colors and black-and-white patterns. The outcomes of interest were visual detection distance, participants’ descriptions of detectable warning colors, and participants’ ratings of each detectable warnings conspicuity against a particular simulated sidewalk. Detection distance results indicate that pedestrians with visual impairments were able to see most combinations of detectable warning and sidewalk from 8 ft away, but fewer were able to see them at greater distances. Detectable warnings that were similar in color to the sidewalk were seen by few participants, indicating that visual cues provided by the truncated-dome texture itself are not sufficient to ensure visual detection. The luminance contrast between the detectable warning and the sidewalk was an important factor for predicting the likelihood that a detectable warning would be seen. Besides luminance contrast, regression analyses indicated that some other characteristics of detectable warnings were generally associated with high detection rates and high conspicuity ratings, including color (reds and yellows rather than achromatic) and reflectance (lighter colors rather than darker colors). Additional recommendations for detectable warning visual characteristics are provided.

Impact of In-vehicle Voice Control Systems on Driver Distraction: Insights From Contextual Interviews

Many in-vehicle systems have multimodal interfaces and allow mobile device connectivity to embedded and cloud-based systems. However, some drivers continue to use their hand-held devices regardless of whether the device can be synched with the vehicle. In these situations, drivers appear to rely more on voice interfaces given the perception that they may be safer to use for performing in-vehicle tasks. Drivers use of these systems within their own vehicles was explored using contextual interviews conducted in Seattle, WA and Rockville, MD. The study was conducted on planned routes with 64 participants, who were asked to perform voice control tasks for communication, navigation, accessing information, and entertainment while driving. The interviews were video recorded and a researcher rode along and logged the responses and errors made during the voice interactions. Cognitive workload was assessed using the NASA TLX (Task Load Index). The study showed that drivers are willing to use various voice control devices using smartphones, original equipment manufacturer (OEM) installed voice systems, or a combination. The types of errors made and the level of workload perceived varied among the different voice tasks, indicating that varying levels of distraction can occur with voice interfaces.

Familiarity and Distraction Affect Drivers’ Responses to In-Vehicle Warnings for a Hazard that is Not Yet Visible

On-road experiments measured drivers’ initial responses to in-vehicle emergency electronic brake light (EEBL) warnings indicating hard braking by some vehicle in the lane ahead. Participants drove within a platoon of four research vehicles on an Interstate highway with other traffic present. Speed and time gap between the participant’s vehicle and the vehicle immediately ahead were measured before and after a warning was triggered. This paper examines the effects of prior training about EEBL warnings and driver distraction on responses to the warning when the hazard (braking vehicle in lane ahead) was blocked from view by an intervening vehicle. An EEBL warning, if effective, should encourage drivers to immediately reduce their speed and increase the time gap between their vehicle and the vehicle ahead. We hypothesized that the warning would be more effective for drivers who had received training about the meaning of EEBL warnings as compared to naïve drivers; and more effective for visually distracted drivers as compared to drivers who were looking ahead but saw no hazard when the warning was triggered. Results suggest that speed reductions following onset of the warning were increased by training and decreased by distraction. The EEBL warning elicited the most robust response from drivers who were not distracted and from those had been trained about the warning system. There was no evidence for an interaction between these two factors. These results suggest that training drivers about vehicle safety systems may increase proper behavioral responses, thereby increasing the effectiveness of in-vehicle warnings.

On-the-Road Driver Behavior Experimentation Issues and Approaches

This panel addresses a research methodology that is becoming more essential for driving safety research. The methods of driving simulation and naturalistic driving have been prominent and remain important, but their limitations are becoming more evident. On-the-road experimental methods offer some of the advantages of naturalistic driving while providing a degree of experimental control and manipulation more typical of simulator experiments. Five expert researchers will discuss both scientific and pragmatic issues in the conduct of on-the-road experimentation, making use of lessons learned from their own studies. Each panelist will present a brief perspective on the problem from the point of view of their experience and expertise. This will be followed by an open discussion period.