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Visual acuity is defined as the spatial resolution capacity of the visual system. It is commonly accepted that the foveal, or on-center visual acuity, is far better than the peripheral acuity due to retinal and cortex constructions [Anstis, 1998]. Other factors affect the way an individual visually perceives their surroundings as well. This paper seeks to illustrate the variance of the visual field in terms of several compounding factors including acuity, depth perception, and color perception and their effect on a vehicle operator's visual field. Within accident reconstruction, digital renderings of an accident are often re-created from the vantage point of one or more persons to illustrate what they may have perceived prior to and during an event. However, typically no compensations are made to account for any general and/or individual visual based sensory degradation.

Heavy vehicle cabs of the ‘cab-over’ type construction have very little structure in front of the driver which can be used to absorb energy during a frontal collision. As part of a project to develop a crashworthiness standard for Heavy Goods Vehicles (HGV) cabs [1], a phase of dynamic computer simulations was carried out. The simulations used Finite Element (FE) models analysed with the LS-Dyna3D software, and concentrated on ‘cabover’ type vehicles. Typical accidents, involving frontal collisions, were reconstructed for potentially survivable truck to truck impacts. The residual space was defined by the geometry of a 95%ile dummy and it’s intrusion was recorded for each analysis. Also using dynamic simulations a Type Approval-like test scenario was developed which was representative of the generic frontal impact accidents. A summary of all the simulation results is presented by this paper.

HOLES burned in pistons are usually associated with the word preignition. There are, however, other causes for piston burning, such as, detonation and excessive temperatures, and these as well as the fundamental factors causing preignition, are discussed in this paper. The author suggests that spark-plug condition is probably the most important factor involved in preignition. Considering the other causes of piston burning, operation, maintenance, and possibly fuel variations, all become important because each may contribute to conditions conducive to piston burning.