Toplu taşıma sefer sıklıklarını belirlemede rıske duyarlı bir yaklaşım

The traditional objective to transit network frequency setting is the minimization of total in-vehicle and station waiting times. The data used in this decision-making process are generally the mean forecasted travel times and travel demand. When the bus line frequencies are set based on these data, passengers occasionally experience excessive travel times due to the changing travel network conditions and congestion. In this study, we obtain optimum line frequencies by considering stochastic travel times and demand, and use the conditional-value-at-risk measure to control the possible large realizations of random outcomes. We characterize the random network parameters by a finite set of scenarios and propose a risk-averse mathematical model. In this bilevel model, the network authority's objective is to increase the system reliability whereas passengers' objective is to decrease their expected travel time. To solve the model, we propose a method that integrates mathematical programming approaches with the genetic algorithm. The validity of the modeling approach is shown with a numerical study.