eae/. Target Population for Injury Reduction from Pre- Published Crash Systems "PTE nternatlona ABSTRACT INTRODUCTION /12/2010

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1 eae/. "PTE nternatlona " Target Population for Injury Reduction from Pre- Published Crash Systems 04/12/2010 Kristofer Kusano and H. Clay Gabler Virginia Tech Copy,ight 20 I 0 SAE International ABSTRACT Pre-Crash Systems (PCS) integrate the features of active and passive safety systems to reduce both crash and injury severity. Upon detection of an impending collision, PCS can provide an early warning to the driver and activate automatic braking to reduce the crash severity for the subject vehicle. PCS can also activate the seatbelt pretensioners prior to impact. This paper identifies the opportunities for injury prevention in crash types for which PCS can be potentially activated. These PCS applicable crash types include rear-end crashes, single vehicle crashes into objects (trees, poles, structures, parked vehicles), and head-on crashes. PCS can benefit the occupants of both the striking and struck vehicle. In this paper, the opportunity for injury reduction in the struck vehicle is also tabulated. The study is based upon the analysis of approximately 20,000 frontal crash cases extracted from NASS / CDS Annually. there are an estimated 16,800 seriously injured occupants (MAIS3+) and 2,900 fatalities in PCS applicable crash types. Rear-end crashes were the most frequent crash type followed by object crashes and opposite direction collisions. Annually PCS applicable crash types comprised over one-third of all occupants exposed to frontal crashes. Furthermore, PCS applicable crash types accounted for 50% of all seriously injured occupants and 56% of all fatalities in all frontal crashes annually. Although only 12% of occupants were unbelted, these un belted occupants accounted for 45% of the serious injuries (MAIS3+) and 57% of the fatalities. Although a similar number of occupants were exposed in the striking and struck vehicle in rear-end crashes. there were double the number of serious injuries yet half the number of fatalities in striking vehicle occupants. This paper identifies h pote tial population of occupants that are exposed and Injured In crash types where there is possibility for PCS intervention. This paper does not present any estimates for benefits of PCS implementation. INTRODUCTION Pre-Crash Systems (PCS) integrate features of active and passive safety systems to reduce both crash and injury severity. Many of these systems use millimeter wave radar to detect an impending crash [l,zja]' Upon detection of an impending crash, the PCS system can provide early warning to the driver and activate automatic braking even if no evasive action is taken. Some of the sys.tems can also activate seatbelt pretensioners and adjust seat position to prepare the occupant for a crash. This can enhance the effectiveness of these advanced passive systems if the restraints can be deployed in a low risk fashion. PCS systems are useful for detecting objects in front of the vehicle. Most systems that are being introduced onto the market claim to track vehicles and large objects. Thus the major benefits of PCS will be for rear-end crashes, single vehicle object crashes (i.e. tree, poles, embankments, structures, parked vehicles). and opposite direction crashes. Future enhancements to PCS may allow other crash modes to also benefit from PCS (e.g. side crashes), but these longerterm benefits are yet to be established. The first step in a benefits analysis 'study for any safety system is determining the potential population that could benefit from the implementation of the system. Knowing the exposure to applicable crash events will then lead to determining the extent of which those exposed can benefit. Therefore, the objective of this paper is to characterize the ex osure and injury of occupants involved in crash types which PCS could prevent or mitigate. Hereafter, these crashes will be collectively referred to as PCS applicable crash types.

2 Although it is clear that vehicles equipped with PCS could benefit from crash prevention and mitigation, non-equipped vehicles involved in crashes with PCS equipped vehicles could also benefit greatly. The crash type of most note in this case is a rear-end crash, where the front of one vehicle impacts the rear of a leading vehicle traveling in the same direction. Occupants in the striking, or bullet, vehicle will experience different injury risk and patterns than occupants in the collision partner, or struck, vehicle. By examining characteristics of both the striking and struck vehicle in rearend crashes, the true benefit of system implementation can be realized. METHODOLOGY Target cases were selected from the National Automotive Sampling System / Crashworthiness Data System (NASS/ CDS) from years 1997 to NASS/CDS is a nationwide crash data collection program sponsored by the U.S. Department of Transportation. The data collected includes thousands of crashes on a representative, random sample of minor, serious, and fatal crashes. Trained crash investigators collect data from police reports, crash site investigation, interviews, and medical records. For this study, only cases that involved late model year vehicles (model year greater than 1998) and a crash with fi'ontal damage as the first harmful event were selected. Furthermore, only passenger vehicles were examined. Exposure to crash types is also presented for NASS/CDS year 2008 as an estimate of current annual exposure. As the number of MY vehicles has increased every year, a simple average of cases over this time period would underestimate the annual crash exposure and injuries. In light of this, the most recent year of NASS/CDS was used as a better estimate of annual exposure and injury outcomes. The larger twelve year dataset (NASS/CDS ) was used when computing distributions, as the larger sample size will yield the most accurate estimates. All vehicles and occupants were weighted using NASS sample escalation factors to produce nationally representative sample of crash exposure. Crash types were determined by examining pre-crash events, movements, and accident type as coded in NASS/CDS. This sorting methodology was adapted from Eigen et al [ ]. Three crash types were examined: rear-end crashes, object crashes, and opposite direction crashes. These crash types were identified as the most likely scenarios where most PCSs could successfully intervene in a crash. Rear-end crashes included crash types of the lead vehicle decelerating, stopped, and moving at a lesser speed in the same travel lane with no vehicle maneuver, as well as rear-end crashes with a vehicle maneuver prior to the crash. Object crashes included single vehicle crashes with a road departure, no vehicle maneuver, in which the most harmful event was a pole, tree, embankment, structure, or parked vehicle. Structures refer to any fixed object along the roadside. Opposite direction crashes involved a vehicle traveling straight or negotiating a curve and colliding with a second vehicle that encroached into the subject vehicle's path. Both vehicles for opposite direction crashes were examined together, as crash type and expected injuries were similar. For rear-end crashes, the crash partner for each striking vehicle was also analyzed. The struck vehicle was found by searching each case for another vehicle with rear damage as the first. harmful event. Only passenger vehicles were examined but model year of the rearimpacted vehicle was not considered. Because PCS systems can benefit all occupants of the vehicle, all passengers were examined for both striking and struck vehicle crash types. This includes the driver, front passenger, and any occupants in rear seats. Exposure to each crash type was found by summing the weighted number of crashes and occupants, as determined by NASS. The severity of each injury in NASS/CDS is recorded using the Abbreviated Injury Scale (AIS). AIS is a 1-6 numeric scale for classifying injury severity with 1 being minor injury and 6 being fatal injury. The maximum AIS (MAIS) is defined as the most severe injury suffered by an occupant. MAIS injuries were adjusted for fatalities in NASS/CDS, as occupants can expire without sustaining an AIS6 injury. MAIS for fatally injured occupants was set to 6 regardless of maximum AIS level. The number of seriously injured occupants was found by summing occupants that sustained a maximum AIS injury level from 3 to 6 (MAIS3+). In addition, Harm was used as an injury metric. Harm is a weighted average of societal and economic cost associated with injury. For example, a severe head injury may have longer lasting societal effects than a broken rib. Injury distributions were found by summing the recorded AIS injury for each body region. This study differs from the study conducted by Eigen et al in several ways [ ]. Our focus is on the potential for injury reduction from fleetwide implementation of PCS. The potential for reduction of specific injuries (e.g. head, chest, and extremities) is investigated in addition to the global measures of MAIS and Harm. For rear crashes the striking and struck vehicle were analyzed separately to identify the possible injury prevention benefits for occupants of PCS equipped cars as well as occupants of collision partner vehicles. This study also considers injury distribution by seatbelt use and presents a tabulation of occupant exposure both from a historic and annual basis. Furthermore, this study examines only PCS applicable crash types (rear-end crashes, single vehicle road departure object crashes, and opposite direction crashes).

3 Table 1. Exposure and Injury jor PCS Applicable Crash Typesjrom NASS/CDS 1997 to 2008 Crash Type Rear-End Object Opposite Direction Total (pes Applicable) All Weighted Vehicles Occupants MAIS3+F 1,903,197 12,528,395 22, ,704 11,110,231 53, , ,376 37,855 3,012,952 I 4,011,002!. 113, ,088 11,240, ,225 Unweightcd Fatalities Vehicles Occupants MAIS3+F Fatalities 2,842 10,467 7,663 20,972 37,785 3,093 4, ,113 2, ,386 2, ,592 9,223 1, ,992 29,512 3, RESULTS EXPOSURE Table 1 shows the estimated number of vehicles and occupants exposed to PCS applicable crash types, the number of seriously injured occupants (MAIS3+), and the number of fatalities (NASS/CDS ). In addition, the exposure and injury for all frontal crashes is tabulated. For these initial exposure results, only striking vehicles were examined in rear-end crashes. Rear-end crashes accounted for the most vehicles with 1.9 million vehicles and 2.5 million occupants. Object crashes and opposite direction collisions accounted for 826,000 and 284,000 vehicles, respectively. Over this span of time, 4 million occupants were exposed to PCS applicable crash types, which was a third of all occupants exposed to frontal crashes. Although rear-end crashes were the most common crash type, this mode was also the least injurious. Rear-end crashes resulted in only 22,500 seriously injured occupants compared to 53,100 seriously injured occupants for object crashes and 37,900 seriously injured occupants for opposite direction crash types. In total, there were 114,000 serious injuries for PCS applicable crash types, which was 50% of all serious injury in all frontal crashes. Object crashes had the most fatalities with 10,500 followed by opposite direction crashes with 7,660 fatalities and rear-end crashes with 2,840 fatalities. PCS applicable crash types, accounted for over half (56%) of all fatalities for frontal crashes. <table 1 here> Figure 1 shows the distribution of occupants, seriously injured occupants, and fatalities for PCS applicable crash types and all other frontal crashes. PCS applicable crash types account for over a third of all occupants exposed to frontal crashes, half of all seriously injured occupants in frontal crashes, and 56% of all fatalities in frontal crashes. Occupants MAIS3+ Fatalilies 0% 20% 40% 60% 80% 100% _PCS Applicable Crash Types CAli Other Frontal Collisions I Figure 1. Distribution oj Occupants; Seriously Injured Occupants, and Fatalitiesjor PCS Applicable Crash Types and All Other Frontal (NASS/CDS ). Table 2 shows the expected annual number of vehicles and occupants exposed to PCS applicable crash types, the number of seriously injured occupants (MAIS3+), and the number of fatalities based upon NASS/CDS Similar to the historic data, rear-end crashes lead in frequency with 276,000 vehicles and 345,000 occupants. Object crashes follow with 176,000 occupants and opposite direction crashes with 58,000 occupants. Rear-end crashes accounted for the least serious injury with 1,180 occupants. Object crashes had the most seriously injured occupants with 8, 140 followed closely by opposite direction crashes with 7,460 occupants. Likewise object crashes resulted in the most fatalities with 1,530 followed by object crashes with 1, 190 fatalities and rear-end crashes with only 181 fatalities. <table 2 here>

4 Table 2. Annual Exposure and Injury for PCS Applicable Crash Types (NASS/CDS 2008) Weighted Crash Type Vehicles Occupants MAIS3+F Unweighted Fatalities Vehicles Occupants MAIS3+F Fatalities Rear-End 275, ,827 1,179 Object 157, ,764 8,139 Opposite 43,044 57,950 7,456 Direction Total (PCS 476, ,540 16,774 Applicable) All Frontal 1.181,543 1,502,380 34, ,525 1,193 2,900 4, ,087 1, ,138 4, SEATBEL T USE PCS may have especially high benefits for occupants who do not use their seatbelts. Seatbelts are one of the most effective safety systems in vehicles. Unbelted occupants are at a much higher risk of injury than are belted occupants. By reducing the kinetic energy of a crash, PCS can reduce the injury risk for these unrestrained occupants. Figure 2 shows the distribution of occupants, serious injury (MAIS3+), and fatalities in the three crash PCS applicable types for NASS/CDS years 1997 to Although unbelted occupants accounted for only 12% of all occupants, they sustained 45% of all serious injury and 57% of all fatalities. This shows that unbelted occupants are disproportionately represented in serious injury and fatalities. Potentially, half of the benefits of PCS will accrue to unbelted occupants. Seatbelts provide protection in many crash types beyond PCS applicable crash types, for example to prevent ejection. Seatbelts will continue to be essential in PCS-equipped vehicles. Occupants MAIS3+ Fatalilies 0% 50% 100% Belted OUnbelted Figure 2. Distribution of Occupants, Serious Injury (MAIS3+), and Fatalities by Seatbelt Use in PCS Applicable Crash Types (NASS/CDS ) INJURY DISTRIBUTION The injury distribution was found for the occupants in case vehicles for years Table 4 shows the number occupants that experienced serious (AIS3+) head, chest, and extremity (upper and lower) injuries for PCS applicable crash types with the percentage of the total frontal crash population. PCS applicable crash types accounted for almost one-third (30%) of occupants experiencing serious head injury. For serious chest injury, PCS applicable crash types accounted for 38% of all seriously injured occupants. PCS applicable crash types accounted for 28% of all serious extremity injuries in frontal crashes. <table 3 here>

5 Table 3. Number of Occupants with Serious Head, Chest, and Extremity Injuries for PCS Applicable Crash Types with Percentage of Total Frontal Crash Population (NASS ) Number of Seriously Injured AIS3+ Occupants AIS3+ Crash Type Head Chest Injuries Injuries Rear-End ,488 Object ,220 Opposite Direction ,476 Total (PCS Applicable) ,185 % of Seriously Injured Occupants AIS3+ AIS3+ AIS3+ AIS3+ Extremity Head Chest Extremity Injuries Injuries Injuries Injuries 69, % 25.3tYo 16.9% 37, % 9.4% 9.0% % 2.9% i.8% 114, % 37.6% 27.7% All Frontal 302, , Figure 3 shows the distribution of hann and serious injury by body region for all rear-end striking vehicle occupants. Head injury accounted for the most hann with 35% followed by spine (19%) and chest (16%). For serious injury, chest injury was the most frequent with 33% followed by head (21 %) and lower extremity (17%). t 21.0% Spine 1-_",. 11'1.6% Chest % '.-- Head li iii iiiiiiilii iii iii " iii" i33 4 iii. 9 0 Lo.ExlT. Up.ExIT. Abdomen Unspec % 16 % 32.9% Head. ii iiiiiliii ii iilljiii,. ii 22i9. 5 o;.t: 1 Spine Chest Lo.Extr. Up.Extr. Abdomen 18. % 25. % 13.8 ;' J :21.3% 0"10 10"10 20% 30"10 Frequency (%j 40"10 Figure 4. Injury Distribution of Harm and Serious Injury by Body Region for Occupants in Object 0% 10"10 20% 30"10 Frequency (%) 40% Figure 3. Distribution of Harm and Serious Injury by Body Region for All Rear-End Striking Vehicle Occupants Figure 5 shows the injury distribution by body region for opposite direction crash types. Head, chest, and lower extremities comprised the most hann (42%, 16%. and 12%. respectively). Chest, head, and lower extremity injury accounted for the most AIS3+ injuries. Figure 4 shows the injury distribution by body region for object crash types. Head injury accounted for the most hann (30%) followed by spine and chest injury (21% and 18%, respectively). Chest, lower extremity, and head injury accounted for the most serious injury (AIS3+).

6 Table 4. Number of Occupants, Serious Injuries (MAIS3+F) and Fatalities for Rear-end by Striking and Struck Vehicles for NASS/CDS Vehicle Striking Struck Total Weighted Vehicles Occupants MAIS3+F ,369,206 12, , ,462 6,202 1,213,415 2,282,668 18,662 Unweighted Fatalities Vehicles Occupants MAIS +F Fatalities 676 1,375 2,052 1,339 3, ,479 2, ,818 5, Head Chest Lo.Extr. Spine Up.Extr. Abdomen ' T ' % 1-_... l!5 %.., ;' 1- _ % ;159% 42.0"/. Head iii iiiiiili iii iiili %-""l =-l Up.Extr.... liii! ll Lo.EKtr. Spine Chest 0.6 Y. :.. Unspec. Neck cp.:ilz N.t:;: 0% 10% 20% 30% 40% 50% Frequency (%) Figure 5. Injury Distribution Harm and Serious Injury by Body Region for Opposite Direction Occupants Abdomen Neck Un spec. J.e-X' 8: % 20% 40% 60% Frequency ('Yo) 80% Figure 6. Injury Distribution by Body Region for Rearend Striking Vehicle Occupants INJURIES IN THE COLLISION PARTNER For rear-end crashes, the injuries in the striking vehicle and struck vehicle were analyzed separately. Table 4 shows the number of occupants, serious injury (MAIS3+), and fatalities for both striking and struck vehicles in rear-end crashes. Only cases that had matching striking and partner vehicles were considered. There were approximately half as many seriously injured occupants in struck vehicles than striking vehicles, while there were twice as many fatalities in struck vehicles compared to striking vehicles. <table 4 here> Figure 6 shows the Injury distribution by body region for rear-end striking vehicle occupants. Head and upper extremity injuries accounted for the most harm in this crash type (34% and 19%, respectively). Similarly, the head comprised 64% of serious injuries (AIS3+). Figure 7 shows the injury distribution for rear-end struck vehicle occupants. Spine injury was most prevalent in this crash type with 33% of harm. Head and lower extremity followed with 22% and 13%, respectively. Chest injury accounted for the most serious injury with 37% followed bv head injury with 30%. Harm is a measure of societal and economic cost associated with specific injuries. In the AIS injury scale, spine injury is classified as any damage to the spine, including the cervical spine, while neck injuries are constrained to injuries to the vasculature or musculature of the neck. Whiplash, a common minor injury in rear-end collisions, is classified as an AISI spine injury. Furthermore, serious spine injury (AIS3+) has a higher cost than any other injury level in the computation of Harm. Therefore, even a small increase in the number of serious spine injuries causes a large increase in Harm caused by spine injuries. Thus, the combination of more AIS 1 spine injuries and more AIS3+ spine injuries in struck vehicle occupants compared to striking vehicle occupants most likely caused the trend of more serious and harmful spine injuries in struck vehicle occupants.

7 Spine Noj;' ' % 29.5% lo.extr. Up.Extr. Unspec. Neck A.bdome n ' 13.3 _ %,... 8;:.:._ _.. 3.3% 0% 20% Frequency (%) 40% Figure 7. Injury Distribution by Body Region for Rearend Struck Vehicle Occupants DISCUSSION As presented, there is a great opportunity for crash mitigation with PCS technology. Not only is there an opportunity for occupants of equipped vehicles to benefit, but occupants of collision partners also stand to greatly benefit from these systems. Late model year vehicles are equipped with advanced safety systems such as multi-stage airbags and load limiting seatbelts. Thus, examining NASS/CDS case years from presents an estimate of the target population that could have benefited from PCS. The results from NASS/ CDS 2008 are used as an estimate for current annual exposure. Annually over a third of all occupants exposed to frontal crashes fall into one of the three PCS applicable crash types. Furthermore, these occupants account for 50% of all serious injuries and 56% of all fatalities for all frontal crashes. Because of the higher incidence of serious and fatal injury for unbelted occupants, this minority of occupants may benefit the most from PCS system implementation. PCS has the potential to greatly mitigate or prevent head, chest, and extremity injury. PCS applicable crash types accounted for 30% of occupants experiencing serious head injury, 38% of occupants experiencing serious chest injury, and 28% of occupants experiencing serious extremity injuries in all frontal crashes. The distribution of occupant injuries differed greatly between rear-end striking and partner vehicles. This is due to the drastically different crash types; the striking vehicle suffers a frontal impact while the struck vehicle involves rear impact. The occupants of struck vehicles most likely sustained less serious injury than occupants of striking vehicles because they were accelerated backwards into their seats. The seatback and seat prevent the occupant from being exposed to excessive displacement. Struck vehicles however had more fatally injured occupants than striking vehicles. Struck vehicle fatalities in rear crashes frequently involved massive occupant compartment collapse which superseded any benefit received by limited displacement. LIMITATIONS This goal of this study was to estimate the magnitude of the population which could have benefited from PCS implementation. The actual benefit of implementation will be system-dependent. The crash types identified in this study were chosen as the most likely scenarios where most precrash systems that are currently available or being developed could mitigate the severity of a crash. The results presented herein should not be considered as the number of preventable crashes or injuries. Risk-benefit analysis will be the subject of future work. In many of the rear-end crash NASS/CDS cases, the struck vehicles had little or no information on occupant injury. There were 3,093 unweighted vehicles selected as rear-end striking vehicles, yet only 1,339 unweighted struck vehicles contained sufficient injury information. Approximately onefourth of NASS/CDS vehicles do not receive a complete inspection. The vehicle may have been repaired by the time of the inspection and, in some cases the owner may not have consented to an inspection. This study focused on classitying PCS applicable crash types on the basis of serious injury. NASS/CDS exclusively contains crashes in which at least one vehicle was towed from the scene and thus does not include numerous minor crashes. Most market-ready PCS systems, however, do not function under low speed crash conditions and thus other safety systems may be more applicable in low severity crashes. NASS/CDS is known to underestimate fatalities. Although the distribution of fatalities may be accurate, the number of fatalities may be conservative. The Fatality Analysis Reporting System (F ARS) provides a better estimate of annual fatalities, but because of the nature of the data collection (i.e. exclusively police accident reports), a direct comparison between F ARS and NASS/CDS may not be possible. METHODOLOGY IMPROVEMENTS The case selection methodology used in this study centers around classifying single vehicle crash types using pre-crash variables. For the PCS applicable crash types selected, this meant the vehicle exited the road without vehicle maneuver. The object contacted, (either a tree, pole, embankment, structure, or parked vehicle) was determined from the most harmful object contacted variable. In the case of multi-event crashes the current methodology could misclassity crashes. For example, a crash could involve a single vehicle departing

8 the roadway, sideswiping a mailbox, then impacting a tree. The most harmful event would most likely be the frontal impact with the tree but the case would not be classified as an applicable crash because a sideswipe was the first impact. For single vehicle crash types selected for this study, 39% had a single event, 29% had two events, and 32% had three or more events. Although the current methodology is a satisfactory method for classifying single vehicle crashes, a more robust evaluation of PCS applicable crash types would consider the whole sequence of events in a crash. In the event of multievent crashes, crashes would be classified by the first harmful event that could benefit from PCS implementation. Multivehicle crash selection (i.e. rear-end and opposite direction) could also benefit from this approach. CONCLUSIONS This study identified the population that was exposed to crash types that could potentially benefit from emerging PCS technology. The study was based upon examination of NASS/CDS for PCS applicable crash types that involved late model year vehicles with fi'ontal damage as the first harmful event. Annually, 579,000 occupants are exposed to PCS applicable crash types. Rear-end collisions were the most frequent crash type, experienced by 345,000 occupants followed by object crashes with 176,000 occupants and frontal-frontal, opposite direction crashes with 58,000 occupants. Although rear-end collisions were most frequent, this crash mode accounted for the least number of seriously injured occupants with 1,180 annually. Object crashes and opposite direction crashes accounted for 8,140 and 7,460 seriously injured occupants, respectively. A similar trend was observed for fatalities. Rear-end crash types resulted in 181 fatalities annually, object crashes resulted in 1,530 fatalities annually, and opposite direction crashes resulted in 1,190 fatalities. In 2008, the three PCS applicable crash types accounted for 40% of all frontal crashes. Furthermore, PCS crash types accounted for 39% of seriously injured occupants and 49% of fatalities in frontal crashes in From 1997 to 2008, only 12% of occupants were unbelted. Yet, these occupants accounted for 46% of all serious injury and 57% of all fatalities. This paper also presents a distribution of injury by body region for each crash type. PCS applicable crash types accounted for 30% of occupants experiencing serious head injury, 38% of occupants experiencing serious chest injury, and 28% of occupants experiencing serious extremity injuries in all frontal crashes. For rear-end collisions, head, chest, and spine injuries were most harmful. For object crashes, head, spine, and chest injuries were most harmful. For opposite direction crashes, head, chest and lower extremity injuries were the most harmful. For rear-end crashes the striking and' struck vehicle were analyzed separately to identify the possible injury prevention benefits of PCS equipped cars as well as collision partner vehicles. Although the number of occupants in each sample was similar (1,370,000 and 913,000, respectively), there were double the number of seriously injured occupants and half the number of fatalities in striking vehicles compared to struck vehicles. Furthermore, occupants of striking and struck vehicles experienced different types of serious injury. In the striking vehicle, head and extremity injuries accounted for nearly 69% of all harm. In the struck vehicle, spine and head injuries accounted for over half of all harm (55%). Pre-crash systems have a large potential population that may benefit in applicable crash situations. In addition, PCS is a system that not only benefits occupants of PCS equipped vehicles but also occupants of non-equipped collision partners. Identification and characterization of the population exposed to PCS applicable crash types is the first step in this evaluation of safety benefits. Future work will concentrate on computing the injury risk for these crash types and finding the expected benefit from PCS system implementation. REFERENCES 1. Forkenbrock, G., O'Harra, B. (2009). A Forward Collision Warning (FCW) Performance Evaluation. Proc. 21st ESV Conference, Stuttgart, Germany. Paper Number Sugimoto, Y., Sauer, C. (2005). Effectiveness Estimation Method for Advanced Driver Assistance System and its Application to Collision Mitigation Brake System. Proc. 19th ESV Conference, Washington D.C. Paper Number , pp Tokoro, S., Kuroda, K., Kawakubo, A., Fujita, K., Fujinami, H. (2003). Electronically Scanned Millimeter-wave Radar for Pre-Crash Safety and Adaptive Cruise Control System. IEEE Paper Coeling, E., lakobsson, L., Lind, H., Lindman, M. (2007). Collision Warning with Auto Brake - A Real-life Safety Perspective. Proc. 20th lnt. Conference on ESV, Lyon, France, , pp Eigen, A., Najm, W. (2009). Problem Definition for Pre Crash Sensing Advanced Restraints. DOT HS CONTACT INFORMATION Hampton C. Gabler Associate Professor of Mechanical Engineering Virginia Tech Center for Injury Biomechanics 445 ICT AS Building Stanger Street B lacks burg, VA Telephone: (540) gablerlal.vt.edu

9 ACKNOWLEDGMENTS The research team would like to acknowledge Toyota Motor Corporation and Toyota Motor Engineering & Manufacturing North America, Inc. for sponsoring this research project. The Engineering Meetings Board has approved this paper for publication. It has successfully completed SAE's peer review process under the supervision of the session organizer. This process requires a minimum of three (3) reviews by industry experts. All rights reserved. No part of this publication may be reproduced. stored in a retrieval system, or transmitted, in any fonn or by any means, electronic, mechanical, photocopying. recording. or otherwise, without the prior written pemtission of SAE. doi: / Positions and opinions advanced in this paper are those of the author(s) and not necessarily those of SAE. The author is solely responsible for the content of the paper. SAE Customer Service: Tel: (inside USA and ('anada) Tel: (outside USA) Fax: CustomerService@sae.org SAE Web Address: http: 'Iwww.sae.org Printed in USA SAE Internationar