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Federal Highway Administration Research and Technology
Coordinating, Developing, and Delivering Highway Transportation Innovations
| REPORT |
| This report is an archived publication and may contain dated technical, contact, and link information |
 |
| Publication Number: FHWA-HRT-16-058 Date: December 2016 |
Publication Number: FHWA-HRT-16-058 Date: December 2016 |
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This final report presents human factors experimental results that examine the effects of cooperative adaptive cruise control (CACC) on driver performance in a variety of situations. The experiment was conducted in a driving simulator scenario in which the subject driver was embedded in a platoon of CACC-equipped vehicles. CACC is envisioned as an automated vehicle application that complements the capabilities of the vehicle operator without degrading his or her alertness and attention.
The experiment explored the interaction effect of the presence or absence of an auditory warning with the presence or absence of automated braking on drivers’ responses to a maximum deceleration crash avoidance event. The CACC system was effective in assisting drivers in avoiding collisions when both automated braking and an auditory warning were present. Braking or auditory warning alone were not effective in reducing the probability of a collision.
This report informs the discussion among transportation professionals about how automated vehicle applications will be embraced by everyday drivers. The experiment results should be useful to researchers and transportation professionals interested in the effects of automation on driver behavior.
Monique R. Evans, P.E.
Director, Office of Safety
Research and Development
Notice
This document is disseminated under the sponsorship of the U.S. Department of Transportation in the interest of information exchange. The U.S. Government assumes no liability for the use of the information contained in this document.
The U.S. Government does not endorse products or manufacturers. Trademarks or manufacturers’ names appear in this report only because they are considered essential to the objective of the document.
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Technical Report Documentation Page
| 1. Report No. FHWA-HRT-16-058 |
2. Government Accession No. | 3. Recipient’s Catalog No. | ||||
| 4. Title and Subtitle Cooperative Adaptive Cruise Control Human Factors Study: Experiment 3—The Role of Automated Braking and Auditory Alert in Collision Avoidance Response |
5. Report Date December 2016 |
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| 6. Performing Organization Code: | ||||||
| 7. Author(s) Vaughan W. Inman, Steven Jackson, and Brian H. Philips |
8. Performing Organization Report No. |
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| 9. Performing Organization Name and Address Leidos, Inc. 6300 Georgetown Pike McLean, VA 22101-2296 |
10. Work Unit No. | |||||
| 11. Contract or Grant No. DTFH61-13-D-00024 |
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| 12. Sponsoring Agency Name and Address Office of Safety Research and Development Federal Highway Administration 6300 Georgetown Pike McLean, VA 22101-2296 |
13. Type of Report and Period Covered Final Report: 10/1/2013–12/1/2015 |
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| 14. Sponsoring Agency Code HRTM-30 |
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| 15. Supplementary Notes The Contraction Officer’s Representative was David Yang, and the Government’s Task Manager was Brian Philips. |
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| 16. Abstract
This report is the third in a series of four human factors experiments to examine the effects of cooperative adaptive cruise control (CACC) on driver performance in a variety of situations. The experiment reported here was conducted in a driving simulator scenario in which the subject driver was embedded in a platoon of CACC-equipped vehicles. The experiment explored the interaction effect of the presence or absence of an auditory warning with the presence or absence of automated braking on drivers’ responses to a maximum deceleration crash avoidance event. The subject was in the fourth position in a five-car platoon. Dependent measures were crash avoidance (yes/no), manual brake reaction time (seconds), and adjusted time to collision (seconds). The results indicated that a crash avoidance safety benefit was achieved with full CACC (warning and automated braking) but not otherwise. Brake reaction times were longer when automated braking was present, but without the auditory alarm, about half the drivers took too long to react. |
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| 17. Key Words Cooperative adaptive cruise control, CACC, human factors, driving simulation, attention, distraction |
18. Distribution Statement No restrictions. This document is available through the National Technical Information Service, Springfield, VA 22161. http://www.ntis.gov |
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| 19. Security Classif. (of this report) Unclassified |
20. Security Classif. (of this page) Unclassified |
21. No. of Pages 24 |
22. Price N/A |
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| Form DOT F 1700.7 (8-72) | Reproduction of completed page authorized |
SI* (Modern Metric) Conversion Factors
Figure 1. Screenshot. A typical section of the simulated roadway
Figure 2. Graph. Reaction time from onset of braking by platoon-lead vehicle
Figure 3. Graph. TTC results
Table 1. Factorial design of experiment 3
Table 2. Age distribution within the experimental groups
Table 3. Crash results by experimental group
Table 4. Frequency of drivers for whom precise values of adjusted TTC could not be calculated
| ACC | adaptive cruise control | |
| CACC | cooperative adaptive cruise control | |
| CACC-A | cooperative adaptive cruise control with alarm when engine braking authority is exceeded | |
| CACC-AB | cooperative adaptive cruise control with automated braking and alarm when automated braking authority is exceeded | |
| CACC-B | cooperative adaptive cruise control with automated braking but no auditory alarm | |
| CL | confidence limit | |
| FHWA | Federal Highway Administration | |
| GLM | generalized linear model | |
| TTC | time to collision |
