Extracting the Value of the Round Trip Time under Up Peak Traffic Conditions from Simulation

The round trip time has been traditionally found by using calculation methods, either analytically by the use of equations or numerically by the use of Monte Carlo simulation or Markov chains. This paper explores the use of simulation to extract the value of the round trip time. The main reasons for the difference between the value of the round trip time under calculation and simulation are the three random effects: the randomness of passenger destinations (thus making the value of the round trip time a random variable), the randomness of the passenger arrival (driven by a Poisson passenger arrival model) and the effect of bunching (thus making the value of the interval a random variable). The value of the round trip time has been plotted against the system loading level for the case of a single entrance and incoming traffic only. The system loading level has been varied from values as low as 0.05 (i.e., 5%) up to an overloaded system level of 3 (i.e., 300%). Different conditions have been simulated including constant and random passenger arrivals, as well as queues allowed and queues not allowed conditions. Varying these conditions provides an essential insight into the variation of the round trip time and the reasons for it.