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Many accident reconstructions rely on the use of friction factors for the analysis of vehicle speeds. Measurement of the friction factor, or coefficient of friction, at the accident site is usually an important step in achieving a more accurate estimate of the friction factor at the time of the accident. Over the years several on site test methodologies have emerged within the accident reconstruction community. However, little has been published which compares the data and results from the different methods. This paper presents a comparison of some methodologies. A g-analyst1 accelerometer, a VC•20002 accelerometer, and a bumper chalk gun3/radar gun4 are compared for locked wheel friction values under different speed and road surface conditions. Data from the two on board systems are recorded simultaneously. Measurements are made for several stops at each of the speeds and two road surface conditions.

A considerable amount of research has been conducted to evaluate the effects of road surface discontinuities and disturbances on vehicle dynamics and accident causation. This paper addresses the real world effects of these conditions by reviewing the analyses of actual physical evidence of accidents involving alleged road defects. Analysis and testing techniques are described and alternative causative elements are presented.

Accurate scene diagrams are essential to most accident reconstructions. Moreover, the scene diagrams make useful trial exhibits. Electronically Aided Survey Equipment (EASE) can aid the investigator and reconstructionist because it provides the following advantages over traditional measurement techniques: it is faster; it is more accurate; it eliminates transposing errors; it provides elevation measurements; and it permits data to be directly imported into CAD or animation programs. This paper will describe the process from survey to diagram. Furthermore, reconstructionists can load data into a spreadsheet for greater analysis. This paper will additionally cover how electronic survey and data logging can be useful in photogrammetry, in photographic reverse projection, and in obtaining elevations, roadway grades, cross slopes and curve radii for use in speed analysis. A discussion of sight distance analysis diagrams as constructed from survey data is also included.

Major legislation has been established in Europe governing the noise levels of heavy construction equipment. Level limits, test procedures, data acquisition techniques, and future legislation of several European countries are presented specifically for rubber tired front end loaders. Techniques utilized in determining problem source components and methods employed in attenuation of the vehicle to comply with the existing legislation are also discussed. Special attention is given to the spectator level where the regulation limits are most stringent. However, many of the modifications shown are also effective in reducing operator station noise levels.

Methods of measurement, identification, and solution of problem noise and vibration sources on front-end loaders are discussed. An actual noise reduction program successfully completed on a 6.5 yd3 vehicle is used to illustrate the effectiveness of source elimination, application of barrier and absorption materials, and vibration isolation mounts as techniques for the attenuation of noise and vibration.