Pedestrian and Cyclist Impact (eBook)

Table of Contents 7
Foreword 11
Acknowledgements 13
About the Authors 14
Chapter 1 Introduction 15
References 17
Chapter 2 Pedestrian and Cyclist Injuries 18
Introduction 18
Global View of Pedestrian and Cyclist Fatality and Injury Rates 18
Main Pedestrian and Cyclist Injury Database Sources 20
Distribution of Pedestrian Injuries 21
Distribution of Cyclist Injuries 23
Injury Risk as a Function of Age and Sex 29
The Distribution of Vehicle Impact Speeds 30
Injuries from Vehicle and from Ground Contact 34
Injury Risk as a Function of Vehicle Size and Type 34
Injuries and Disabilities 37
Pedestrian Injury Trends over Time 38
Concluding Remarks 38
References 40
Chapter 3 Pedestrian and Cyclist Impact Kinematics 44
Introduction 44
Sources for Studying Pedestrian and Cyclist Movement 45
Classification of Pedestrian and Cyclist Impact Configurations 45
Pedestrian Sideswipe Collisions 47
Wrap Projection 48
Pedestrian/Cyclist Head Contact in Wrap Projections 53
Forward Projection 56
Post Head Impact Kinematics for Forward and Wrap Projection 58
Cases 58
Concluding Remarks 61
References 61
Chapter 4 The Relationship between Vehicle Impact Speed and Pedestrian and Cyclist Projection Distance 63
Introduction 63
Stages of Pedestrian and Cyclist Projection 64
Post Impact Separation from the Vehicle 65
Effective Coefficient of Retardation in the Ground Contact 66
Accident Data 66
Staged Tests 69
Comparison between Accident Reconstructions and Staged Tests 70
Regression Models Relating Impact Speed to Pedestrian 72
Projection Distance 72
Physics Based Models Relating Impact Speed to Pedestrian 74
Projection Distance 74
Theoretical Considerations: The Particle Projection Model 75
Wrap Projection 78
Pedestrian Forward Projection 79
Confidence Limits for Vehicle Impact Speed Prediction 82
Other Models 82
Concluding Remarks 84
References 84
Chapter 5 Injury Mechanisms and Injury Criteria 87
Introduction 87
Head Injuries 88
Head Injury Criteria 89
Spinal Injuries 94
Thorax Injuries 96
Abdominal Injuries 98
Pelvis Injuries 99
Lower Extremity Injuries 99
The Long Bones: Femur, Tibia and Fibula 100
The Knee 104
The Ankle and Upper Extremities 105
Concluding Remarks 105
References 105
Chapter 6 Vehicle Design Standards for Pedestrian and Cyclist Safety 110
Introduction 110
Bodies Developing Pedestrian Safety Standards 111
Types of Test Proposed 112
Subsystem Tests: Legform Impactor to Bumper 113
Upper Legform to Bonnet Leading Edge 115
Headform to Bonnet Top: Adult and Child 118
Implementation into Legislation 120
Concluding Remarks 122
References 122
Chapter 7 Mathematical Formulations for Impact Modelling 126
Introduction 126
Notation 127
Timing 128
Impulse and Momentum 129
Single Segment Formulation Using Momentum Considerations 131
Post Primary Impact Kinematics 132
Head Contact Time 132
Post Head Impact Kinematics 133
Pedestrian Formulation Using an Ordinary Differential 135
Equation (ODE) Approach 135
Rigid Body ODE Approach with a Hinge Segment 138
Three-Dimensional Effects 141
Problems with a Rigid Body Approach 142
A Finite Element Approach to Pedestrian Impact 143
Concluding Remarks 146
References 146
Chapter 8 Models for Simulating Impact 148
Introduction 148
Pedestrian Physical Dummy Models 148
Mathematical Models 149
Multibody Models 152
Finite Element Models 156
Application of Finite Element Pedestrian and Cyclist Models 163
Concluding Remarks 163
References 166
Chapter 9 Ground Contact Injuries 170
Introduction 170
Relative Severity of Ground versus Vehicle Impact 172
Variability of Ground Contact 173
Vehicle Impact Speed Effects 174
Influence of Vehicle Design 176
Possible Methods to Reduce Ground Contact Injuries 179
Concluding Remarks 180
References 180
Chapter 10 The Influence of Vehicle Design on Pedestrian and Cyclist Injuries 182
Introduction 182
Definitions 183
Influence of Vehicle Mass 186
Influence of Vehicle Stiffness 187
Influence of Overall Vehicle Shape 189
Bumper Shape 192
Influence of Bumper Height onWhole-Body Kinematics 195
Secondary Bumper 196
Bumper Lead 198
Bumper Stiffness 198
Bullbars 200
Shape of Bonnet and Bonnet Leading Edge 200
Bonnet Leading Edge Stiffness 205
Head Impact on the Bonnet/Windscreen 207
Evaluation of Production Vehicles Via Proposed Pedestrian 211
Safety Regulations 211
Concluding Remarks 214
References 214
Chapter 11 Conclusions and Future Perspectives 220
Introduction 220
Epidemiology and In-Depth Crash Injury Studies 220
Kinematics 222
Population Variations to Injury and Disability Outcomes 223
Modelling and Simulation 224
Cost Benefit Calculations of Future Gains for Pedestrians and 225
Cyclists 225
Immediate Problems of Pedestrians and Cyclists in Low Income 225
Countries 225
Separation of Fast Flowing Traffic from Pedestrians and Cyclists 226
Reduction of Vehicle Impact Speeds with Pedestrians and 226
Cyclists 226
Implementation of Pedestrian Friendly Front-End Design in 227
Those Vehicles Which Are Most Likely to Collide with 227
Pedestrians and Cyclists 227
Design Requirements for Future Vehicles 227
Requirements for a Global Pedestrian/Cyclist Friendly Standard 228
Conclusion 229
References 229
Index 231