INTRODUCTION OF A NEW HIGH SPEED LINE IN A HIGH DENSITY TRAFFIC AREA: A SIMULATION EXERCISE

The introduction of a new high speed line in an important railway area including a main station has a significant impact on the whole railway area. A sound estimation of the consequent modification of the traffic pattern is therefore required, together with the study of the new track layout of the area. Many different solutions can be considered for the traffic pattern, the track plan, and the traffic control system. The optimized solution choice involves a set of computer-based simulation models of the variables of the problem (track layout, rolling stock, signaling, and traffic density) and the costs and benefits evaluation. This paper describes the study carried out for the area of Florence, Italy, where two high-speed lines converge together with seven other ordinary speed lines, carrying a dense traffic of long distance passenger trains, commuter trains, and freight trains. The area includes the main station of Florence and a number of minor stations. The study includes a model of the track layout of the area, a set of proposed solutions of the traffic timetable for the whole area, the model of the different types of rolling stock, the model of the signaling system, the simulation of the traffic alternative scenarios, the simulation of the utilization of the platform tracks in the main station, the evaluation of the effect of perturbations on the traffic capacity, and the evaluation of the results. The details of the area layout and expected traffic are presented, together with examples of graphic timetables, track occupation diagrams, traffic capacity evaluation, and perturbation effects.