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  • Characteristics of Voice-Based Interfaces for In-Vehicle Systems and Their Effects on Driving Performance: Researchers at NHTSA’s Vehicle Research and Test Center are conducting a closed-course experiment to assess the relative distraction potential associated with selected characteristics of voice interfaces relevant to in-vehicle information systems generally and to 511 traveler information systems in particular. Results of this research may be used to improve the design and function of future voice interfaces for in-vehicle systems.

  • System for Assessment of Vehicle Motion Environment: The objective of this project is to develop and validate a measurement system that can quantify the specific motions that vehicles exhibit as they move in traffic under the full array of traffic operations. In subsequent projects, the measurement system will be used to gather information such as reaction to other drivers cutting in front, normal following distance and typical lane change trajectories to create a foundation for development of ITS countermeasures that identify the need for intervention.



Wireless Phone Research: Driver Distraction and Use Effects on the Road: This research is intended to provide empirical data to describe how drivers use wireless phones while driving and, if possible, support or refute the move toward hands-free wireless telephones. The knowledge gained by performing the above research will help NHTSA to gain useful insights into the safety benefits/disbenefits of conventional hands-free and enhanced hands-free (AutoPC) as compared to hand-held wireless telephones.

  • The Effects of Voice Technology on Test Track Driving Performance: Implications for Driver Distraction: The objective of this study was to compare the distraction potential of speech-based versus visual/manual interfaces for selected transactions of differing complexity performed while driving. Twenty-one subjects completed two sets of (8) laps around a 7.5-mile test track. They drove an instrumented vehicle, while performing a combination of car following, peripheral target detection, and secondary (in-vehicle) tasks of varying complexity. Subjects performed one set of laps with each of two interfaces, including voice-based and visual/manual. Secondary tasks included baseline tasks (radio tuning, phone dialing), simple tasks (message retrieval plus voice memo creation), and complex tasks (simple task components plus phone dialing and information retrieval from automated phone systems). Measures of driving performance, target-detection, secondary task performance and eye movements were recorded. Analyses are underway to determine whether the voice-based interface reduced the relative distraction potential for secondary tasks of varying complexity. Generally, differences between tasks were stronger than differences between interface conditions. Measures of car-following performance, target detection, and secondary task performance revealed differences attributable to task complexity. Differences between the two interfaces were observed on peripheral target detection measures, although effects were not large. Overall, the voice-based interface did not appreciably reduce the distraction potential of the secondary tasks, relative to the visual/manual interface. A final report is in preparation. This work is being conducted in collaboration with Transport Canada.


  • NHTSA Driver Distraction Public Meeting / Internet Forum

  • Driver Distraction with Wireless Telecommunications and Route Guidance Systems: The overall objective of this project is to measure the device-related demands placed on drivers by in-vehicle devices and determine, in a comparative fashion, workload minimization design features. The classes of in-vehicle devices evaluated include route navigation systems and wireless phone systems. These two classes of technology span a range of cognitive, auditory, and visual demands, may impose significant distraction on the driver, are likely to be simultaneously present and used, and are being actively marketed and developed to have greater functionality. It is for these reasons that route guidance systems and wireless phone systems were selected as the technologies to be examined in this program of research. The research described in this report had the following objectives: 1) characterize the impact of route guidance system destination entry and wireless telephone use on vehicle control and driver eye glance behavior on a test track; 2) assess the influence of individual differences, as indexed by a battery of cognitive tests, on the susceptibility to distraction as indicated by disruption in vehicle control and driver eye glance behavior during destination entry and wireless telephone use while driving; and 3) examine the validity of a proposed SAE recommended practice to assess whether or not a given route guidance destination entry function ought to be allowed while the vehicle is in motion.

  • Driver Behavior Baseline Data Collection in Support of ITS Crash Avoidance Countermeasure Performance Specification Programs: NHTSA has a program to develop performance specifications for crash avoidance countermeasure systems for rear-end, road departure, lane change/merge, backing, and intersection crashes. For example, forward-looking collision avoidance systems (FCAS), which are intended to prevent rear-end crashes, monitor the zone in front of the host vehicle and provide warnings to the driver if the headway to a lead vehicle presents a potentially dangerous situation. In order to determine how these systems should present warnings to drivers it is important to first determine how drivers normally conduct themselves while driving, in the absence of any technological collision avoidance support. NHTSA was conducted a series of studies to collect data to characterize such things as driver car following behavior, driver lane keeping behavior, and driver lane change/merge behavior. Testing was performed to measure the baseline behavior and performance of a representative sample of the licensed driving population unaided by any collision avoidance systems.
  • The first study conducted dealt with driver car following behavior. VRTC has been asked to develop a model that predicts Eyes-off-Road-Time (EORT) or some variant of it (e.g., probability of at least one glance away from the road scene) as a function of car following parameters. Informal observations indicate that drivers spend more time with their eyes on the road scene as they get closer to a lead vehicle. There is also scientific evidence that suggests a relationship between car following distance or time headway and following vehicle driver attention to the road scene.

  • Haptic Feedback / Rear-End Collision Avoidance System Research: An examination of the performance and effectiveness of haptic driver feedback for Rear-End Collision Avoidance Systems (RECAS) was conducted. Data were collected to assess the effectiveness of RECAS equipped with haptic driver feedback in helping drivers to avoid rear-end crashes. Drivers' acceptance of these systems and the manner in which they may take control of the vehicle to avoid a collision with a vehicle of obstacle ahead were assessed. Drivers' behavior and reactions to the RECAS in general, and the haptic feedback specifically, were recorded using a MicroDAS. Questions such as whether haptic feedback is beneficial and elicits appropriate driver responses in terms of crash avoidance and whether drivers are comfortable with the manner in which the RECAS takes control of the vehicle were assessed.

  • Drowsy Driver: NHTSA completed a unique observational study of drowsy and inattentive driving on public roads. Eight test participants were selected from populations thought to be at heightened risk for drowsy driving (e.g., shift workers, military personnel on weekend leave, college students on breaks). The volunteers had their personal vehicles instrumented with the MicroDAS system of unobtrusive data acquisition. Steering, lane keeping, travel speed, and other engineering measures were recorded along with road scene video and video of the driver's face to capture eye closure and eye glance behavior. These data were analyzed post hoc with the drowsy driver detection algorithm developed by W. W. Wierwille and his colleagues at Virginia Tech. In addition, algorithm false alarms were analyzed to determine if they might be attributed to increased driver inattention to the driving task, as evidenced by eye glances away from the road scene or distracting in-vehicle activities. This field study provided real-world data collected on passenger car drivers rather than commercial truck drivers, driving their own vehicles rather than a test vehicle, driving on trips of their own choosing rather than experimental routes, and driving on public roads rather than on a test track or in a simulator.

  • Data Acquisition System for Crash Avoidance Research (DASCAR): The Data Acquisition System for Crash Avoidance Research (DASCAR) is a tool that was developed by the National Highway Traffic Safety Administration (NHTSA). DASCAR allows data collection from a broad range of vehicle models and types and provides researchers with the ability to record information on driver behavior and performance, vehicle performance, and roadway environment. The tool also makes it possible to measure driver performance in relation to any vehicle design characteristic and allows updating of existing models of driver/vehicle behavior and performance to reflect the characteristics of vehicles of current manufacture.

    Further development of the DASCAR has led to the development of the MicroDAS. The MicroDAS is a smaller system with extended capabilities of the DASCAR The system features easy installation, small form factor, greater than 22 hours of full-motion video data collection, event triggering, pre/post-triggering, and is low cost. Because the system is portable and easily installed, The MicroDAS permits the measurement of driver behavior and performance in-situ, using drivers' own vehicles, ensuring "real world" naturalistic data collection, thus eliminating concerns about vehicle familiarity.

U.S. Department of Transportation National Highway Traffic Safety Administration
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