Seven hundred motor vehicle/bicycle accidents were investigated in-depth, data coded and stored, and analysis performed with the objective of determining countermeasures. Exposure measures were taken at each accident site during the same period of time under matching environmental circumstances. Univariate analysis of the data file was conducted to provide some visibility into the principal factors of the accident population. Analysis was conducted for causation, injury, and exposure measures. Limited exposure matching with accident variables prevented comprehensive exposure analysis. Nonparametric analysis of selected accident variables was conducted with a function flow model of the accident process which is human behaviour orientated. The accident model commenced with the multidisciplinary state variables of human, vehicle, environment, addressed the human functional flow of risk-taking, search, detection, evaluation, decision, and action. Under the action function, nonhuman factors of vehicle and environmental functional failures were introduced. Variables were coded mutually exclusive for bicyclist and driver. The analysis established that the principal cause of these accident types was human error with the bicyclist making the majority of the errors. The age groups of the bicyclists were statistically overrepresented. There was no significance associated with bicyclist sex. Volume 1 is B 19486.
Abstract