contents Introduction xi CHAPTER 1 Use of Throw Distances of Pedestrians and Bicyclists as Part of a Scientific Accident Reconstruction Method 1 Introduction 2 Basis of Speed Calculation 2 New Results Based on Real Accidents 4 Kinematics of Impact 5 Relation between Throw Distances and Impact Speed 5 Injury Relation to Impact Speed and Throw Distance 9 Conclusion 11 References 13 CHAPTER 2 A Study of a Method for Predicting the Risk of Crossing-Collisions at Intersections 15 1. Introduction 16 2. Analysis of Traffic Accident Data 17 Breakdown of Crossing-Collisions 17 Combinations of Intersection Types and Accident Parties 18 Pre-crash Driving Patterns of Primary and Secondary Parties 19 3. Quantification of Crossing-Collision Risk 20 Method of Estimating Crossing-Collision Risk 20 Method of Estimating P(A) for Individual Accident Factors 20 4. Estimation of Crossing-Collision Probabilities for Different Types of Intersections 21 Estimation Method 21 Data Used and Estimated Results 22 2019 SAE International v
vi 5. Estimation Of Crossing-Collision Probabilities by Driving Pattern of Non-Right-Of-Way Vehicles 23 Estimation Method 23 Data Used and Estimated Results 23 6. Estimation of Crossing-Collision Probabilities by Type of Other Vehicle 24 Estimation Method 24 Data Used and Estimated Results 24 7. Estimation of Accident Reduction Effect of Various Safety Measures 25 Estimation of the Effect of Infrastructure Implementation on Reducing Accidents 25 Estimation of the Effect of a Driver-Support System on Reducing Accidents 25 Comparison of Accident Reduction Effect of Infrastructure Implementation and Driver-Support System 27 8. Conclusions 27 References 28 CHAPTER 3 Road Bicycle Dynamics in the Presence of Idealized Roadway Irregularities 29 Introduction 29 Literature Review 30 Steady-State Cornering 30 Modeling of Contacts with Irregularities 31 Derivation of Pitchover Conditions 32 Dynamics of Ramp Climbing 34 Test Program 35 Bicycle Dynamics Over Idealized Roadway Irregularities 35 Conclusions 36 References 36 Nomenclature 38 CHAPTER 4 Analysis of Bicycle Pitch-Over in a Controlled Environment 39 Introduction 40 Defining Pitch-Over 40 Dynamics 41 Center of Gravity (CG) Location 41 Minimum Deceleration Required for Pitch-Over 41
vii Minimum Velocity 41 Instant Center of Rotation at Pitch-Over Initiation 42 Front Wheel Lift Off 42 Testing 42 Setup 42 Bicyclist 43 Landing Zone 43 Load Plates 43 Sync Flash 44 Data Acquisition 44 Dowel Shooter 44 Video and Still Camera Documentation 44 Test Articles 45 Procedures 45 Error 46 Test Series 47 Brake Application 47 Dowel Insertion 47 Barrier Impact 47 Data Processing and Motion Analysis 47 Results 48 Bicycle Damage 48 Brake Application Test Series 48 Dowel Insertion Test Series 50 Barrier Impact Test Series 53 Discussion 56 Conclusion 57 Acknowledgments 58 References 58 Appendix A - Bicycle Configuration 59 CHAPTER 5 Influences on the Risk of Injury of Bicyclists Heads and Benefits of Bicycle Helmets in Terms of Injury Avoidance and Reduction of Injury Severity 61 Introduction 61 Framework of Evaluation 65 Documentation Method of GIDAS 66 Descriptive Outcome Processing 66 Accident and Injury Patterns of Bicyclists 66
viii Injury Severities of the Heads of Bicyclists Involved in an Accident 69 Usage of Bicycle Helmets by Different Types of Bicyclists and In Relation to Different Accident Characteristics 70 Effectiveness of the Bicycle Helmets 72 Statistical Evaluation of the Influence of Different Parameters on Head Injuries 74 Damage Pattern on the Helmet 75 Conclusion 78 References 79 Acknowledgments 81 CHAPTER 6 Wrap Around Distance (WAD) of Pedestrians and Bicyclists and Relevance as an Influence Parameter for Head Injuries 83 Introduction and Objectives 84 Measurement of the WAD in Real Accidents 87 Study Tasks 88 Accident Studies Based on GIDAS 88 Database 89 Evaluation Structure of the Study 89 A. Descriptive Analysis 90 A.1. Injury Severity Grade of the Head (AIS Head) 90 A.2. Direction of VRU Related to Driving Direction of the Car 92 A.3. Collision Speed of the Car 93 A.4. Head Impact Point Lateral Distance to Longitudinal Car Axis 93 A.5. Head Impact Point WAD 94 A.6. Influence of the Age of the VRU to the Injury Severity of the Head 94 B. Multivariate Analysis 95 B.1. Statistical Analysis of Influence Importance of WAD, Impact Speed of the Car, and Body Height and Age of the VRU for Head Injury Occurrence 96 Conclusion and Discussion 101 References 102 Acknowledgments 103
ix CHAPTER 7 Cycling Characteristics of Bicycles at an Intersection 105 Introduction 106 Experiment Method 108 Site of the Investigation 108 Subjects of the Investigation 110 Investigation Items 110 The Extent to Which Traffic Regulations Were Observed 110 Cycling Characteristics of the Cyclists 110 The Velocity of the Cyclists 110 Trajectory 110 The Timing the Cyclists Stopped Pedaling 111 Method of Analysis 111 Results of the Experiment 111 Percentage of Cyclists Who Confirmed Safety at the Intersection 111 The Percentage of Cyclists Coming to a Stop at the Intersection 112 Velocity of the Cyclists 113 Changes in the Bicycles Velocity when Entering into the Intersection 113 Trajectory of the Cyclists 115 Investigation of TTI 115 Timing of the Warning Given to Cyclists to Prevent a Collision 117 Conclusion and Discussion 118 1. Confirming It Is Safe to Cross and Coming to a Stop at the Intersection 118 2. Cyclist Velocity 119 3. Changes in Cyclists Speed when They Entered the Intersection 119 4. Bicycles Trajectory 119 5. Timing of the Warning to Prevent Collisions 119 References 120 Acknowledgments 120 About the Author 121