Three-dimension model of motorisation and fatality rates

F igure 3.10 Three-dimension model of motorisation and fatality rates (Navin, 1994) 

2 Linking traffic risk, motorisation and personal risk with time 

Vmax is the maximum number of vehicle kilometres, k is the time lag in years, and X, w, z, y, and c are constants 

Oppe (1989) assumes that fatality rates follow a negative exponential learning function in relation to the number of vehicle kilometres and time. This method has been found to be most effective when the components describing the time series behave slowly over time as follows  

Vt is the number of vehicle kilometres travelled in that year, 

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