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Showing papers by "Kenneth L. Campbell published in 1993"


Journal ArticleDOI
TL;DR: Characteristics of the operating environment were found to have larger effects on the accident rate than tractor configuration (except for the bobtail), and rates varied by a factor of up to 6.8, depending on the road type.

57 citations


Journal ArticleDOI
TL;DR: An effort to identify and rank vehicle collision scenarios in order to create a "collision typology" that could aid in the assessment of the potential benefit of accident avoidance technologies suggested that in collisions at nonsignalized intersections, older drivers often stopped and then pulled out into oncoming traffic, while younger drivers more often failed to stop at all.

42 citations


Journal Article
TL;DR: The high rate of loss among the settled women along with the difference between the nomadic and settled samples supports the contentions that there may be substantial variation among populations in intrauterine mortality and that the contribution of fetal loss to fertility differences among populations may be more important than has been suspected.
Abstract: There have been few investigations of intrauterine mortality in non-Western populations that have used techniques capable of detecting early pregnancy loss. We report here the initial results of a prospective study of fetal loss among the Turkana of northwest Kenya. Over 300 nomadic and settled women provided early morning urine samples for 3 consecutive days. Chorionic gonadotropin (hCG), a marker for pregnancy, and markers of ovarian cyclicity (LH, PdG) were determined with solid-phase enzyme immunoassays. Pregnancy was detected in 11% of nomadic women and in 22% of sedentary women of reproductive age. Follow-up surveys revealed that 45% of all pregnancies among settled women were lost; nearly 70% of pregnancies detected in the first trimester were lost. In contrast, none of the nomadic women experienced fetal loss. Because of the small sample sizes, these results must be interpreted cautiously. Nevertheless, even a conservative estimate of the fetal loss rate among the settled women is high compared with Western experience. Anthropometric data suggest that nutritional stress may contribute to the difference between the two populations. There is also some indication that risk of fetal loss in the settled population is associated with parity. The high rate of loss among the settled women along with the difference between the nomadic and settled samples supports the contentions that there may be substantial variation among populations in intrauterine mortality and that the contribution of fetal loss to fertility differences among populations may be more important than has been suspected.

32 citations


01 Jan 1993
TL;DR: Men had a higher risk than women of experiencing a fatal crash, while women had higher rates of involvement in injury crashes and all police-reported crashes.
Abstract: Passenger-vehicle travel data from the 1990 Nationwide Personal Transportation Survey (NPTS) were combined with crash data from the 1990 Fatal Accident Reporting System (FARS) and the 1990 General Estimates System (GES) to produce crash involvement rates per vehicle-mile of travel. Elevated rates were observed for drivers 16-19 and 75 and over. The oldest drivers had the highest fatal involvement rate, while the youngest drivers had the highest rate of involvement in all police-reported crashes. Men had a higher risk than women of experiencing a fatal crash, while women had higher rates of involvement in injury crashes and all police-reported crashes. For the covering abstract of the conference see TRIS 00663162.

6 citations


Journal Article
TL;DR: In this paper, the authors compared three sources of truck travel data: the Truck Inventory and Use Survey conducted by the Bureau of the Census, the National Truck Trip Information Survey (NTIS), and annual estimates published in "Highway Statistics" by the Federal Highway Administration.
Abstract: The number of miles traveled each year by the U.S. large-truck population is a topic of interest for many reasons, one of which is safety. Although the number of accidents involving large trucks may be easily calculated from accident data, it is often more informative to know their risk of accident involvement per mile of travel. This requires accurate travel data. Compared in this paper are three sources of truck travel data: the Truck Inventory and Use Survey conducted by the Bureau of the Census; the National Truck Trip Information Survey conducted by the University of Michigan Transportation Research Institute; and annual estimates published in "Highway Statistics" by the Federal Highway Administration. Each data source yields different estimates of annual travel by large trucks, which is to be expected considering the difficulty of collecting travel data. The overall conclusion, however, is that the Truck Inventory and Use Survey and the National Truck Trip Information Survey estimates are reasonably close to each other, whereas "Highway Statistics" estimates are significantly higher. The implication of this finding is that the procedures used by the states and the Federal Highway Administration to generate "Highway Statistics" data lead to artificially and systematically high estimates of travel by large trucks.

3 citations