A timed stochastic coloured Petri net (CPN) model of a single runway is presented in this paper that is capable of analyzing the effect of the availability of taxiways on the capacity of the runway and on the timing of a given schedule. The developed CPN model is governed by elementary Air Traffic Control (ATC) principles (one aircraft at a time on runway, arrivals priority on departures), and takes the effect of the aircraft threshold speed categories and their landing weights into account. The model is realized by using the Design/CPN program package. The model has been verified and validated by using runway occupancy times generated by REDIM. For planning optimal sequences a small scale window method is used.