In this work, the probability of disturbances to road traffic is calculated on the basis of the theory of Telephone Traffic, and with the aid of Erlang's rejection formula. It is shown that the concepts of "basic capacity" and "practical capacity" used in the 1950 edition of the Highway Capacity Manual are based on 40 and 22% disturbed cars (rejected from desired speed), respectively, to 2-lane traffic in 1 direction on a rural highway free from intersections. Other findings and results are also provided.
Abstract