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Vehicle safety devices, similar to new pharmaceuticals and medical devices, may be associated with injury risks as well as injury benefits. Available analytical methods from the public health, medical and vehicle safety fields are described. A literature review is provided that includes an overview of relevant principles of risk analysis, risk-benefit terminology, fields of application, types of risk-benefit analysis, methods of quantification, assumptions, data needs, treatment of uncertainties, and risk-benefit criteria. Several applicable quantification methods are further described, including Quality Adjusted Life-Years, Disability Adjusted Life-Years, and Normalized Injury-Fatality Costs. Data input sources are described, including accident sampling and analysis, and paired comparison test and simulation methods.

A review, analysis and enumeration are presented of factors relevant to motorcycle airbag feasibility research. This includes: an update of the status of related research in the motorcycle airbag feasibility field; relevant experience and factors from the car airbag field; additional unique factors and considerations for motorcycles; and the potential need to address motorcyclist out-of-position riding; other sizes of riders; motorcycle seating layout variation; resistance to and consequences of unintended deployment on a motorcyclist; neck injury criteria and dummy neck biofidelity; injury risk-benefit considerations; environmental exposure on motorcycles; and discussion of feasibility definition and factors.

This paper summarizes a comprehensive research program of the ride qualities of long-haul trucks. Factors are identified which contribute significantly to differences in ride quality between various truck models and configurations over a range of actual operating conditions. Detailed measurements of six floor and seat accelerations and driver and passenger ride ratings were made on ten in-service trucks over five segments, ranging from “smooth” to “rough,” of a typical California freeway. The experimental methodology is reviewed and validated, and example data and preliminary comparisons between the objective and subjective measures are presented.

Factors involved in improving motorcycle brake systems and components are reviewed. Component and system functional requirements are reviewed from the standpoints of manual control factors, performance, and required operating conditions. Component response properties of example contemporary machines are presented. Results show that, for motorcycle hydraulic disc systems, hysteresis, wet disc response, and other response features related to manual control can be key factors.

Preliminary results of a study to develop lateral-directional handling test procedures for motorcycles are presented. One is a steady-state turn, accomplished with a range of forward speeds and turn radii. The other is a single lane change maneuver, using various degrees of severity and forward speeds. Several example motorcycles were studied analytically and via full scale tests. Data from onboard instrumentation show the effects of vehicle and operational differences on selected response and performance measures. This paper comprises a progress report, and the work is continuing.

A theoretical and empirical view is taken of motorcycle lateral-directional dynamics, handling, and rider control behavior. The analytical development includes equations of motion for the vehicle and a multiple loop feedback model for the control response of the rider/cycle system. Connections with manual control and vehicle response data are shown. The effects of changing fork geometry, operating conditions, and tire lag properties are discussed. Implications are drawn for handling requirements, vehicle design, and rider control techniques.

Analytical results describing moped lateral-directional response properties are presented. Design characteristics of four example mopeds related to directional handling are presented and compared with sample motorcycle properties. Resultant moped dynamics are quantified and compared. Using a nominal moped example, the sensitivity of the vehicle dynamics to operational and design variables, such as speed, loading and tire properties, is shown. Implications for rider/moped handling are reviewed.

Analytical and experimental studies of the transient and oscillatory behavior of motorcycles are reported. Three example vehicles were used. The effects of adding load, changing operating conditions, and modifying the vehicle configuration are shown. The phenomenon known as cornering weave is illustrated and interpreted.

Motorcycle braking test procedures and results are presented. Both straight line and combined cornering and braking maneuvers were used. Test conditions included various initial speeds, turn radii, surface skid numbers, and levels of braking effort for two instrumented motorcycles. The effect of braking on transient yaw response in turns is demonstrated, also. Overall, the results show that repeatable safety related response and performance measures can be obtained using the prescribed procedures with expert test riders.

The design and development of a top fuel drag motorcycle are reviewed from the standpoints of performance, stability and handling, and rider safety. The paper begins with a summary of design requirements related to longitudinal performance, lateral/directional stability and control, structural properties, rider factors, organizational rules, and the fact that drag racing is a spectator sport. A contemporary top fuel dragster design is used as an example case study. Analytical results illustrate the effects of aerodynamics, and varying other design parameters, on performance and stability. A principal result is that adequate down load must be maintained on the front tire. The results suggest that safety and good handling need not compromise ultimate performance, and that the required tradeoffs can be guided by analysis at the design stage.

Results of a study to specify, develop, and test the handling characteristics of a prototype research safety vehicle are reported. Handling requirements which were used to evaluate the transient and steady state response and performance are described. These requirements and criteria were based on a review of contemporary results in the area of handling and controllability, and they combine vehicle performance envelopes and driver-centered considerations. The resulting criteria are used as handling objectives in the testing and evaluation of a prototype small sedan.

A theoretical and experimental investigation of the effects of antilock braking (ALB) on motorcycle braking in a turn (BIT) is described. The analyses involved computer simulation of the dynamic interaction among rider, motorcycle, ALB, and roadway during BIT maneuvers; and instrumented full scale BIT tests with expert and novice riders. The analyses and full scale tests used an example all mechanical, independent front and rear ALB system. The results showed that ALB can help maintain motorcycle stability in straightline and gradual turns at high and excessive brake force levels. In more severe turns, the motorcycle can capsize at low brake force levels, below those which are typically needed to trigger ALB operation. As a consequence, from a fundamental standpoint, contemporary conventional ALB systems cannot be considered to influence or improve motorcycle stability during limit braking in moderate or near limit turns.

An updated evaluation of the effects on predicted injuries of an example crush protective device (CPD) proposed for application to All-Terrain Vehicles (ATVs) is described. As in previous evaluations, this involved extending and applying the test and analysis methods defined in ISO 13232 (2005) for motorcycle impacts, to evaluate the effects of the example CPD in a sample of simulated ATV overturn events. Updated modeling refinements included lowering the energy levels of the simulated overturn events; accounting for potential mechanical/ traumatic (compressive) asphyxia mechanisms; refining and calibrating the force-deflection characteristics of helmet, head, legs and soil so as to reduce potential over-prediction of head and leg injuries; and calibrating the simulation against aggregated injury distributions from actual accidents.

Rider control techniques and the handling qualities of all terrain vehicles (ATVs) are discussed. A manual control view is taken of the rider/vehicle/terrain system, including control inputs to the ATV and perceptual feedbacks to the rider. Steering control, overturning stability, and acceleration limits are considered. The important role of rider body movement is discussed. Comparisons are drawn with motorcycles and off road buggies. Vehicle system requirements that can be important from a design standpoint are reviewed.

The Advanced Crash Avoidance Technologies (ACAT) program initiated by the National Highway Safety Administration had two major objectives. These were to develop a standardized Safety Impact Methodology (SIM) tool to evaluate the effectiveness of advanced technologies in avoiding and mitigating specific types of vehicle crashes; and to develop and demonstrate objective tests that are used in the SIM to verify the safety impact of a real system. Honda and Dynamic Research Inc. (DRI) have been developing and applying such SIMs for several years and have a Cooperative Agreement with NHTSA to further develop a SIM that provides an estimate of full systems safety benefits at a national level.