A case study that illustrates the importance of combining crash data with a thorough analysis in an auto reconstruction investigation.
A motorist exiting a rural freeway was struck by a motorist on the intersecting State Route at the top of the exit ramp. At the westbound exit ramp from the Interstate freeway the State Route a stop sign is posted at the end of the ramp requiring exiting traffic to stop before entering the State Route. However, the eastbound off ramp traffic is not required to stop before entering the State Route. A stop sign is posted on southbound State Route at the ramp terminal. This is an unusual traffic signing pattern for interstate off ramps. Expert observations of the operation of this intersection showed that a large proportion of the eastbound off ramp traffic slowed down at the end of the ramp, expecting to stop at the State Route.
Many automobile accidents are complex cases with multiple events during a single accident. The aim of forensic investigations of such (and all other) accidents is to reconstruct the sequence and the severity of events during the accident and then to establish cause and- effect relationships between the injuries (or damages) and the probable factors - vehicle design (e.g. brakes, structure, airbags); vehicle operator (e.g. distracted driver, alcohol impairment, reduced vision); and operating conditions (e.g. fog, failed traffic sign, excessive speed, icy road).
Tree stand accidents occur frequently during hunting season, causing a variety of injuries from broken bones to paralysis and death. Tree stand accidents involve a variety of causes, including falls from the tree stand, collapse of the tree stand, fires, self inflicted gunshot wounds, and asphyxiation. A study by the Center for Disease Control examined hunting accidents from 1979-1989. 214 of 594 deer hunting related accidents involved tree stands. 52% of these tree stand accidents were due to falls from the stand, 32% were due to collapse of the tree stands.
This issue of Forensic Clues is the second installment of an examination of ladder accidents. Last month we explored stepladders, this month we will be discussing extension ladders. Ladder accidents are a very common occurrence. Over half a million people annually seek medical attention due to ladder accidents. Over three hundred people are killed yearly in these often preventable accidents. This is a serious problem.
Rock and ice climbing have become increasingly popular in recent years. Climbing is now a popular form of exercise and adventure, and a great way to enjoy the outdoors. Unfortunately the greater numbers involved in the sport has led to greater number of accidents. Climbing gyms have brought climbing to areas without outdoor rock resources. These indoor gyms use artificial holds to simulate rock walls. Indoor climbing gyms typically have climbs ranging from twenty feet to fifty feet, or more. Bouldering areas are shorter in height, with adequate padding to protect climbers from falls without the need for ropes.
In the last installment (STN, Jun, 2007), I stressed the importance of distinguishing between an actual bus stop and the waiting area across the street from it in terms of safety. But the selection of the stop and waiting area also involves concerns for student security. Sometimes, there are trade-offs that must be made. These trade-off are often complex and subtle. But they must be made correctly.
Material science is a broad field that has applications in numerous fields. In product injury cases, material science can help identify defects, determine causes of accidents, determine failure modes, and identify inconsistent manufacturing processes.
Fishing and boating accidents result in thousands of injuries each year. The U.S. Coast Guard reported 3331 injuries and 709 fatalities due to boating accidents on both recreational and commercial vessels. There are many causes for these accidents, including collisions with objects or other vessels, drowning, electrical and mechanical failures, interaction with unguarded machinery, and others. There are various acts and laws that govern accidents at sea. This issue of Forensic Clues will examine some of the preventable accidents caused by defective machinery and equipment that occur at sea, and a brief overview of the laws and regulations affecting product liability litigation related to maritime accidents.
Accident reconstruction involves attempting to determine the sequence of events of an accident and is a crucial part of product liability cases. Understanding exactly what occurred in an accident gives an engineer the best chance of preventing the accident from occurring again. Often there is limited information to base conclusions on what really happened in an accident. Understanding what goes into accident reconstruction will help attorneys understand what information is crucial to this process. Witness testimony is unreliable at best but must be analyzed and cross referenced with the other available information.