The Hinton train disaster.

In February of 1986 a head-on collision occurred between a freight train and a passenger train in western Canada killing 23 people and causing over $30 million of damage. A Commission of Inquiry appointed by the Canadian government concluded that human error was the major reason for the collision. This report discusses the factors contributing to the human error: mainly poor work-rest schedules, the monotonous nature of the train driving task, insufficient information about train movements, and the inadequate backup systems in case of human error.

Time vs. distance as measures of exposure in driving surveys.

A survey of drivers carried out in Ontario in 1988 has provided data on time spent driving as well as the distances driven for licensed drivers of both sexes in six age groups and three regions. Substantial differences were found in times, distances, and distance/time ratios among these groups. Men drove 50% greater distances, but spent only 30% more time driving than women; speed, averaged over each day's driving, was lower for older drivers than for younger drivers. Differences in speed reflect differences in the driving done in urban or rural areas, and differences in the opportunity for road crashes; such differences, whether based on units of time or distance, will also affect both the comparisons of accident rates and the perceptions of risk among different groups of drivers. A definition of exposure to risk of road crash is required that considers both time and distance appropriately.

The role of exposure in comparisons of crash risk among different drivers and driving environments.

Crash rates based on drivers, driver-kilometers, and driver-days in the denominator were compared, using survey estimates of time and distance driven and the annual frequency of traffic crashes in Ontario. Rates by age, sex, and region were computed for all crashes and for crashes resulting in injury or fatality. Young male drivers remained at high risk for all types of denominator; older women had high rates when distance was included in the denominator. When time spent driving was substituted, men and women drivers over 60 had very similar rates. For comparisons of rural residents with urban and northern residents, time and distance give equivalent results. These findings suggest that apparent differences in crash risk per kilometre, whether for older women or for urban drivers, is explained by differences in typical driving speed and environment. Exposure time is better than distance to explain crash risk among drivers and regions with very different driving patterns and environments.

Human response to buffeting in an all-terrain vehicle.

Suitably prepared subjects were exposed to the vibration imposed by driving a personal-type all-terrain vehicle over a heavily plowed track. Acceleration was measured in the Z-axis at the seat of the vehicle, and in the X, Y, and Z axes at the hip and head of the subjects. Acceleration peaks, rates of onset, durations, and frequency ranges were determined and a spectral analysis conducted. Results showed that, for this vehicle under the test circumstances, the subjects respond with a low-frequency (less than 4 Hz) oscillation at approximately 0.5 Gz above nominal, on which are imposed numerous peaks of 1 to 5 G, or higher with rates of onset within the range measured, of 20 to 100 G/s. Although the measurement system did not conform to ISO (International Standards Organization) requirements, the results suggest that continued exposure would exceed the ISO 1-min limit for "health and safety."

Eosinophilic fasciitis in association with thyroid disease: a report of three cases.

We describe 3 patients whose findings fulfilled all the criteria for eosinophilic fasciitis. Unexpectedly, all 3 were found to have thyroid disease: 2 Hashimoto's disease and 1 Grave's disease. One patient also developed multiple subcutaneous nodules of a rheumatoid type. All have been followed for at least 3 yr and shown marked clinical improvement. Corticosteroids were employed in only 1 case.