Nobuyuki Kuge

Lane-change detection using a computational driver model.

Objective: This paper introduces a robust, real-time system for detecting driver lane changes. Background: As intelligent transportation systems evolve to assist drivers in their intended behaviors, the systems have demonstrated a need for methods of inferring driver intentions and detecting intended maneuvers. Method: Using a “model tracing” methodology, our system simulates a set of possible driver intentions and their resulting behaviors using a simplification of a previously validated computational model of driver behavior. The system compares the models simulated behavior with a drivers actual observed behavior and thus continually infers the drivers unobservable intentions from her or his observable actions. Results: For data collected in a driving simulator, the system detects 82% of lane changes within 0.5 s of maneuver onset (assuming a 5% false alarm rate), 93% within 1 s, and 95% before the vehicle moves one fourth of the lane width laterally. For data collected from an instrumented vehicle, the system detects 61% within 0.5 s, 77% within 1 s, and 84% before the vehicle moves one-fourth of the lane width laterally. Conclusion: The model-tracing system is the first system to demonstrate high sample-by-sample accuracy at low false alarm rates as well as high accuracy over the course of a lane change with respect to time and lateral movement. Application: By providing robust real-time detection of driver lane changes, the system shows good promise for incorporation into the next generation of intelligent transportation systems.

Physiological responses to workload change. A test/retest examination.

The purpose of this study is to examine the test/retest consistency of physiological responses induced by mental tasks. Fifteen healthy male university students were recruited as participants. They were instructed to perform a 5-min Multi-Attribute Task Battery (MATB) trial three times successively. The task difficulty level of the tracking task of the second trial was set as medium (M). The first one was set as more difficult (H) and the last trial was easiest (L). The difficulty levels of the other two tasks (resource management and system monitoring) of the MATB were identical for all three trials. The participants repeated this procedure on three different days separated by at least a 1-day interval. The order of the tasks was the same for all repeated trials, i.e., H-M-L. Tissue blood volume from the tip of the nose using a laser Doppler blood flow meter, skin potential level (SPL), ECG from three leads on the chest, systolic time intervals (pre-ejection period, left ventricular ejection time), and hemodynamic parameters (stroke volume, cardiac output) were recorded during the task trials and before and after 5-min resting periods. The participants reported their subjective workload via NASA-TLX after each task trial. Autonomic nervous system parameters derived from the above-mentioned signals, subjective workload scores, and performance indices of MATB were analyzed, and test/retest reliability was investigated. The results showed that a significant test/retest correlation was obtained for SPL for more participants than in the other parameters, although there were large individual differences.

Quantifying Car following Performance as a Metric for Primary and Secondary (Distraction) Task Load: Part A — Modification of Task Parameters

Driver impairment as a result of attention-related factors is a common concern to many areas of safety research in driving. Previously, the “coherence technique” was developed to provide several metrics of performance in relation to the continuous task of car following presumed to require vigilance and perceptual capacity (Brookhuis, De Waard, & Mulder, 1994). This study examines a modified version of this technique that is more natural. This modified technique was sensitive to both increased primary and secondary (distraction) task load.

Influence of a Driver Support System on Situation Awareness and Information Processing in Response to Lead Vehicle Braking

Situation Awareness (SA) is critical to safe driving in a dynamic traffic environment. SA is predicated on the timely sampling of information in the driving environment. Distraction from secondary tasks can interrupt this sampling resulting in increased traffic conflicts and crashes. It is hypothesized that SA may be improved if sampling is augmented with (redundant) non-visual feedback about relevant information in the driving scene. The current study examined a Driver Support System (DSS) based on continuous haptic feedback communicated through the gas pedal. This system was evaluated in a driving simulator with participants distracted by a secondary task utilizing the CD player. The results indicate that this DSS improved reaction time, response time, and response appropriateness (safety margin) despite an apparent increase in the transition period between pedals. Various mechanisms to explain these effects are posited.

Multidimensional evaluation of human responses to the workload

Changes in physiological parameters during mental tasks frequently show individual differences and discrepancies among responses invoked by mental tasks. A multidimensional analysis was used in this study to investigate these variations. Fifteen male participants performed a 5-minute multiattribute task battery three times with different levels of difficulty. Principal component analysis was used for seven autonomic nervous system parameters recorded in five blocks including before and after resting periods. The first and the second principal components were plotted on the two-dimensional plane and their patterns were investigated. The results suggest that this method may provide more information on physiological responses induced by mental tasks.

Driver Behavioral Adaptation in Response to a Novel Haptic Driver Support System

Behavior adaptation refers to any change in behavior as a result of the inclusion of a technology that serves a need of the driver other than intended by the technology. Driver support systems that facilitate vehicle controllability may allow for driver resources to be redirected to activities unrelated to that goal. The current study sought to examine the relationship between increased vehicle controllability, which is a design goal of a novel haptic driver support system, and behavioral adaptation as measured by in-vehicle secondary task productivity. Participants drove a simulated rural Minnesota highway with and without the use of a driver support system and with and without engaging in a self paced in-vehicle secondary task. Measures were taken of car-following performance and entropy (controllability) as well as secondary-task performance. Results indicate improved controllability with some marginal behavioral adaptation is acceptable to the extent that the secondary-task engagement is not a risk factor.

Development of a high-functionality tail lamp system in the second phase of the ASV program

A high-functionality tail lamp system aimed at reducing the risk of rear-end collision was developed and installed on the ASV-2, prototype vehicle produced in the second phase of the Advanced Safety Vehicle program promoted by the Ministry of Land, Infrastructure and Transport of Japan. This paper presents experimental findings concerning basic driver cognition and response behavior in connection with stop lamp illumination and approach to a preceding vehicle. It also describes the main functions of the system comprising an emergency braking advanced advisory and large high-mounted stop lamps.