606 Taxicab Driver Homicides: United States and Canada 1980-1994
Appendix B: Hazard Management Approach
This diagram is page 63 of "Assault and Homicide as an Occupational Hazard for Taxicab Drivers: A Hazard Management Approach" by Julie A. Holston. It and the discussion below are reprinted by permission of the author.
Chart: Complete causal sequence of assault of taxicab driver, including amplifiers and interventions.

"The Clark University Causal Model conceptualizes hazardous events as part of a causal sequence, beginning with a human need or want and evolving into a series of occurrences and consequences that cause harm to humans or what they value. The causal sequence consists of seven stages, with one leading to the other through causal pathways. The stages are: Human needs, human wants, choice of technology, initiating events, outcomes, exposure, and consequences. [See: Christoph Hohenemser, Roger Kasperson, and Robert Kates, "Causal Structure" in Perilous Progress: Managing the Hazards of Technology, eds. Robert Kates, Christoph Hohenemser, and Jeanne Kasperson (Boulder, CO: Westview Press, 1985), 25-42.]
The causal sequence of assault or homicide of a taxicab driver begins with two separate sequences of wants, needs and technology, one representing the driver and the other representing the offender, that come together in the initiating event. This model of the causal sequence allows us to view each part of the chain of events, consider what conditions amplify these events, and to consider what interventions may be appropriate to break the chain of events. While not all of the interventions noted would be appropriate, the model allows for a complete view of the problem of taxicab driver assault.
For a detailed analysis of taxicab driver assault and recommendations for interventions see:
Julie Holston, "Assault and Homicide as an Occupational Hazard for Taxicab Drivers: A Hazard Management Approach" (M.A. thesis, Clark University, 1994)."
- Julie A. Holston
Return to the introduction to the 606 homicides report.
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