Choosing ?t
Splitting T(total observation time) into small intervals ?t
Choosing ?t small enough (thus ? = ? t small enough) so that either 1 car or 0 car arrives at the time interval ?t. Namely,
e.g. Given ? = 0.1 minute -1, ?t =1 minute is a possible interval
Observed from Table 2 (cumulative Poisson distribution)
F(0; 0.1) = 0.905; F(1; 0.1) = 0.995; F(2; 0.1) = 1.000
f(0; 0.1) = 0.905; f(1; 0.1) = 0.090; f(2; 0.1) = 0.005