Advanced Automatic Collision Notification Research Report

DOT HS 812 729

May 2019

Advanced Automatic Collision Notification Research Report

Disclaimer

This publication is distributed by the U.S. Department of Transportation, National Highway Traffic Safety Administration, in the interest of information exchange. The opinions, findings, and conclusions expressed in this publication are those of the authors and not necessarily those of the Department of Transportation or the National Highway Traffic Safety Administration. The United States Government assumes no liability for its contents or use thereof. If trade or manufacturers’ names or products are mentioned, it is because they are considered essential to the object of the publication and should not be construed as an endorsement. The United States Government does not endorse products or manufacturers.

Suggested APA Format Citation: Lee, E., Wu, J., Enriquez, J., Martin, J., & Craig, M. (2019, May). Advanced Automatic Collision
Notification Research Report (Report No. DOT HS 812 729). Washington, DC: National Highway Traffic Safety Administration.

Technical Report Documentation Page

1. Report No.

2. Government Accession No.

3. Recipient’s Catalog No.

DOT HS 812 729

4. Title and Subtitle

5. Report Date

Advanced Automatic Collision Notification Research Report

May 2019

6. Performing Organization Code

7. Authors

8. Performing Organization

10. Work Unit No. (TRAIS)

Lee, E., Wu, J., Enriquez, J., Martin, J., Craig, M.

9. Performing Organization Name and Address

National Highway Traffic Safety Administration Office of Vehicle Safety Research

11. Contract or Grant No.

1200 New Jersey Avenue SE. Washington, D.C., 20590

12. Sponsoring Agency Name and Address

National Highway Traffic Safety Administration Office of Vehicle Safety Research 1200 New Jersey Ave SE

13. Type of Report and Period Covered

Final Report

14. Sponsoring Agency Code

Washington, D.C., 20590

15. Supplementary Notes 16. Abstract

This document describes recent progress made by the National Highway Traffic Safety Administration to better understand the safety potential and technical considerations of post-crash technologies such as automatic collision notification (ACN) and advanced automatic collision notification (AACN). These technologies provide automatic notification of a crash when that crash reaches a minimum severity such as air bag deployment. Notification to a public safety answering point (PSAP, or 9-1-1 call center) or telematics service provider (TSP) occurs via cellular signal that allows the vehicle to place a call and transmit data.

Research was conducted on the target population who may benefit from AACN, injury prediction algorithms used by AACN systems, and estimates of costs and benefits (i.e. potential lives saved) that could be realized with implementation of AACN. Finally, research was conducted on development of a procedure to test AACN systems.

17. Key Words

18. Distribution Statement

AACN, ACN, crash notification, telematics, postcrash, injury prediction, pre-hospital care
Document is available to the public from the National Technical Information Service

www.ntis.gov .

19. Security Classif. (of this report)

20. Security Classif. (of this page)

21. No. of Pages

22

Unclassified

33

Form DOT F 1700.7 (8-72)

Reproduction of completed page authorized

Table of Contents

Executive Summar y ......................................................................................................................................i i

I.

Introductio n ......................................................................................................................................... 1

Quantification of Benefits Associated With AACN ........................................................................... 2

II.

i

Executive Summary

This document describes recent progress made by the National Highway Traffic Safety Administration (NHTSA) to better understand the safety potential and technical considerations of post-crash technologies such as Automatic Collision Notification (ACN) and Advanced Automatic Collision Notification (AACN). These technologies provide automatic notification of a crash when that crash reaches a minimum severity (e.g., air bag deployment). Notification to a public safety answering point (PSAP, or 9- 1-1 call center) or telematics service provider (TSP) occurs via cellular signal that allows the vehicle to place a call and transmit data.

The key potential benefits of AACN are faster notification time of the crash, which can lead to emergency medical services (EMS) responding to the scene faster, and the prediction of severe injury. Injury prediction in an AACN system can provide information to EMS on whether or not to transport an occupant to a higher level of care (e.g., a trauma center). Earlier research, as well as updated research conducted for this report, demonstrates that severely injured occupants have significantly higher survival rates when taken to a trauma center compared with being transported to a lower level hospital.

To evaluate the target population, or the group of motor vehicle occupant fatalities that could receive benefit from an AACN system, the agency identified specific characteristics, such as being in a light vehicle and having access to a trauma center within a reasonable time window, that were required in order for these potential benefits to be realized. Another factor necessary for benefits to be realized is for the AACN algorithm to correctly identify the occupant as being severely injured. Research conducted for this report demonstrated that currently recommended thresholds for injury prediction may not be sufficiently sensitive to identifying severely injured or fatal occupants.

Finally, research was conducted on development of a procedure to test AACN systems. Because AACN systems establish voice communications and transmit information from the vehicle, it is possible to detect the presence of these communications without actually obtaining the communications contents, which are typically proprietary. Evaluation criteria were developed and a proof-of-concept test was performed. This research demonstrated the feasibility of developing a repeatable test for AACN.

This report details our findings with respect to ACN and AACN and summarizes our observations to-date about these technologies. The efforts conducted by the agency to date demonstrate that post-crash technologies have the potential to enhance the safety of light vehicles.

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I.

Introduction

There are two post-crash vehicle technologies that provide automatic notification of a crash when that crash reaches a minimum severity (e.g., air bag deployment): Automatic Collision Notification (ACN) and Advanced Automatic Collision Notification (AACN). Notification to a public safety answering point (PSAP, or 9-1-1 call center) or telematics service provider (TSP) occurs via cellular signal that allows the vehicle to place a call and transmit data.

ACN: With this technology, the data transmitted via cellular signal includes the current vehicle location and vehicle identification information (make, model). ACN systems have the potential enable earlier notification of a motor vehicle crash, allowing quicker Emergency Medical Services (EMS) response, andalso improve location identification for first responders (saving time in locating the vehicle).

AACN: With AACN technology, the data transmitted includes everything transmitted by an ACN system (location, vehicle identification information), as well as a prediction of probability of severe injury. AACN systems produce, at minimum, the same benefits as ACN systems, by decreasing notification time. In addition, it is believed that AACN can provide additional benefits such as improved dispatch decision making (e.g., whether to send basic life support, advanced life support or helicopter to scene) and improved transport decision making (i.e., whether to take a patient to the nearest community hospital or bypass the nearest hospital and go directly to a trauma center).

NHTSA has a long history of conducting research related to post-crash notification technologies. These efforts date back to the late 1990s when the agency funded an ACN Field Operational Test to demonstrate the feasibility and benefits associated with ACN systems.¹Since 1986, the American College of Surgeons Committee on Trauma (ACS-COT) has published a resource manual that provides guidance for the pre-hospital triage process through a Field Triage Decision Scheme.²The Decision Scheme protocol is based on an on-scene, sequential evaluation performed by Emergency Medical Services (EMS), consisting of different aspects of trauma patient presentation, with the outcome being a determination of appropriate transport decision for a patient (e.g., hospital or trauma center). Step 1 is defined by physiologic and level of consciousness indicators (e.g., Glasgow Coma Scale) and Step 2 is defined by anatomic signs of injury (e.g., penetrating injury to the head). In 2006, vehicle telematics “consistent with high risk for injury” was added as a criterion to Step 3 of the protocol, meaning that if a patient is negative for Step 1 and 2, the AACN injury prediction can be used to inform transport decision to either hospital or trauma center. To clarify the definition of this criterion, in 2008 the CDC convened a panel of emergency medical physicians, trauma surgeons, public safety, and vehicle safety experts.³The panel considered how real-time crash data from AACN vehicle telematics system and similar systems can be used to determine whether injured patients need care at a trauma center and provided recommendations for telemetry data, such as what data should be transmitted and how to define a “high risk of severe injury.” NHTSA participated in this effort, alongside other governmental and industry experts.

¹Bachman, L. R., Preziotti, G. R. (2001). Automated Collision Notification (ACN) Field Operational Test: Evaluation Report (Report No. DOT HS 809 304). Washington, DC: National Highway Traffic Safety Administration. ²Sasser, S. M., Hunt, R. C., Faul, M., Sugerman, D., Pearson, W. S., Dulski, T., Wald, M. M., Jurkovich, G. J., Newgard, C., Lerner, E. B. & Cooper, A. (2012). Guidelines for field triage of injured patients recommendations of the national expert panel on field triage, 2011. Morbidity and Mortality Weekly Report, 61(RR-1), pp. 1-23. ³Recommendations from the expert panel: Advanced automatic collision notification and triage of the injured patient. Centers for Disease Control and Prevention, National Center for Injury Prevention and control, Division of Injury Response. 2008, available at http://stacks.cdc.gov/view/cdc/5304

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Since 2008, research has been conducted by the NHTSA on the benefits, technical considerations and testing of ACN/AACN systems. This report focuses on this recent research. Although post-crash notification technologies have made significant advances in recent years and optional offerings are becoming widespread among the current U.S. vehicle fleet, voluntarily-reported manufacturer information indicates that these options are not taken in the majority of new car sales. In addition, most current notification systems require paid subscriptions. Some manufacturers offer free temporary trials at vehicle purchase, though the proportion of individuals who continue the service after the free trial lapses is currently unknown.

Post-crash technologies are also becoming more widespread worldwide. For example, the European Union will be mandating embedded automatic collision notification (known as “eCall”) systems beginning in March 2018.⁴This new “eCall” regulation in the E.U. mandates that vehicles must have a permanently installed ACN system that directly calls 112 (the E.U. emergency line) and all owners can opt to use this function or a third party telematics provider. The 112-based eCall service is free of charge (i.e., no subscription fee).

Given worldwide interest along with the NHTSA history with post-crash technology, the agency believes it is now appropriate to update the public on its research efforts and to consider what role the agency should be taking regarding the continued development of AACN systems and their installation in motor vehicles.

II.

Quantification of Benefits Associated With AACN

It is generally accepted that decreased EMS response time following trauma such as a motor vehicle crash is beneficial to medical outcome. Several studies have demonstrated improved odds of survival with reduced response time.^{5 6}For the current effort study, the benefits of earlier notification come from a 2015 study by Wu et al. In that study, FARS data from 2009-2012 was used to show that the mean notification and mean EMS arrival time post-crash for fatalities were 6 minutes and 16 minutes, respectively.⁷Using Kaplan-Meier survival analysis, Wu et al. showed that earlier notification within 2 minutes resulted in a 2% higher survival rate compared with notification later than 2 minutes. Similarly, earlier EMS arrival within 5 minutes also resulted in a 2.7% increase in survival rate. Earlier notification within 1 to 2 minutes (which is potentially achievable with ACN and required cellular coverage) significantly improves crash survivability and could save approximately 177-244 lives annually. Earlier notification will also improve EMS arrival times. Similar benefits have been estimated by others. A 2009 report summarized eight earlier studies from across Europe (and Australia) estimating the potential benefits of automatic collision notification.⁸In addition, four in-depth studies were carried out in the

⁴REGULATION (EU) 2015/758 OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 29 April 2015 concerning type-approval requirements for the deployment of the eCall in-vehicle system based on the 112 service and amending Directive 2007/46/EC ⁵Pons, P. T., Haukoos, J. S., Bludworth, W., et al. (2005). Paramedic response time: Does it affect patient survival?

Academic Emergency Medicine, 12(7), pp.594-600.

⁶Blackwell, T. H., & Kaufman, J. S. (2002). Response time effectiveness: comparison of response time and survival in an urban emergency medical services system. Academic Emergency Medicine 9(4): 288-295 ⁷Wu, J., Craig, M., & Longthorne, A. (2015). Updated estimates of potential traffic fatality reductions with automatic collision notification. In: Proceedings from the 24^thInternational Technical Conference on the Enhanced Safety of Vehicles (ESV); Paper No. 15-0269. Available at www.nhtsa.gov/Research/Biomechanics+&+Trauma/Advanced+Automatic+Collision+Notification+-+AACN ⁸Francsics, J., et al. (2009). Impact assessment on the introduction of the eCall service in all new type-approved vehicles in Europe, including liability/legal issues. Final Report, SMART 2008/55.

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U.K., Netherlands, Finland and Hungary, to update and/or improve upon the earlier studies. These studies estimated between 1% and 10% reduction in fatalities in Europe due to faster notification and improved identification of the location of the incident. Note that these benefits can be realized with ACN systems as well, and do not specifically require AACN systems.

Another factor in survival is the location of treatment (e.g., trauma center or hospital). Trauma centers have designations (Level I through Level IV) based on the resources required to provide various levels of care for traumatic injuries, with Level I trauma centers being considered to provide the highest level of care regardless of injury severity. Non-trauma centers (e.g., local community hospitals) have less access to the resources for treating severely injured patients. MacKenzie et al. (2006) found a 24% reduction in mortality (for deaths within 30 days) when comparing patients that were admitted to a Level I trauma center versus those admitted to a non-trauma center.⁹In a meta-analysis of studies involving establishment of trauma systems, Celso et al. (2006) found a 15% reduction in mortality in favor of the presence of trauma systems.¹⁰Others have documented improved survival rates for occupants treated immediately at a trauma center compared with those who were initially transported to a non-trauma center and later transferred.^{11 12 13}Given this, it follows that the decision of where a severely injured patient is transported after a motor vehicle crash can be aided by information from an AACN system. These benefits are AACN-specific and would not be realized by an ACN system. AACN injury prediction may also provide information on the most appropriate type of emergency response (e.g., Advanced Life Support or Air Medical Services rather than Basic Life Support) required, which may result in highly trained emergency personnel on scene sooner, however these additional benefits are not estimated in the current effort.

To determine the effect of transport decision for the current research, the 2000-2015 NASS-CDS dataset was used to develop relative survival rate ratios between different medical facilities. NASS-CDS documents whether a fatal crash victim was admitted to a Level I or II trauma center (hereafter just “trauma center” versus a Level III center or lower (hereafter just “hospital”) using variable “MEDFACIL.” Additionally, time to death is recorded in hours (up to 24 hours) or days (1+ days) using the variable “DEATH” and fatal outcome was defined using the variable “TREATMNT”=1,2 in the NASS-CDS database.

⁹MacKenzie, E. J., Rivara, F. P., Jurkovich, G. J., Nathens, A. B., Frey, K. P., Egleston, B. L., Salkever, D. S. & Scharfstein, D. O., (2006). A national evaluation of the effect of trauma-center care on mortality. New England

Journal of Medicine, 354(4), pp.366-378

¹⁰Celso, B., Tepas, J., Langland-Orban, B., Pracht, E., Papa, L., Lottenberg, L. & Flint, L. (2006). -A systematic review and meta-analysis comparing outcome of severely injured patients treated in trauma centers following the establishment of trauma systems. J Trauma. 2006; 60(2), 371-378 ¹¹Garthe, E., Mango, N. (2005). Scene triage criteria associated with fatal crashes and potential for use of event data recorder (EDR) data. In: Proceedings from the 19^thInternational Technical Conference on the Enhanced Safety of Vehicles (ESV); Washington, DC. Paper No. 05-0445-O, available at www-nrd.nhtsa.dot.gov/pdf/nrd01/ESV/esv19/05-0445-O.pdf. ¹²Garwe, T., Cowan, L.D., Neas, B. R., et al. (2011a). Directness of transport of major trauma patients to a level I trauma center: a propensity-adjusted survival analysis of the impact on short-term mortality. J Trauma Acute Care Surg; 70: 1118-1127. ¹³Garwe, T., Cowan, L. D., Neas, B. R., et al. (2011b). A propensity score analysis of prehospital factors and directness of transport of major trauma patients to a level I trauma center. J Trauma Acute Care Surg; 70: 120-129.

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One tool to compare the survival probability over time is a non-parametric method proposed by Kaplan and Meier. The Kaplan-Meier is commonly used for medical research and reliability engineering (Kaplan and Meier, 1958; Hosmer and Lemeshow, 1999). The Kaplan-Meier estimator, or life curve, at any time is described by Equation (1).