The railway freight terminals play a key role within the multimodal logistic chain. Therefore, the transit time through these terminals represents one of the most relevant terminal performances and at the same time a key component of the freight transport generalized cost, so that its quantitative analysis is a strategic activity, both in the terminal planning (for the existing and for the future terminal) and in the logistic chain organization. The transit time is composed of deterministic and stochastic components, which increases significantly the problem complexity. The authors developed an original model based on queuing theory allowing the calculation of the transit time for a large variety of terminals. Some pilot applications of the model showed that the arrival distributions of both classes of vehicles are critical inputs for the effectiveness of the results. In this framework the present paper focuses on the theoretical study of these distributions including an extended validation campaign based on data available for an Italian case study (intermodal terminal of Pomezia near Rome). Another relevant aspect, affecting the quality of the model results, is the presence in the terminal of different sizes of intermodal units. In the paper a methodology to take into account these size differences effectively is also explained.
Effect of the distribution of the arrivals and of the intermodal unit sizes on the transit time through freight terminals / Malavasi, Gabriele; A., Quattrini; Ricci, Stefano. - STAMPA. - 88(2006), pp. 905-914. ((Intervento presentato al convegno 10th International Conference on Computer System Design and Operation in the Railway and Other Transit Systems, COMPRAIL 2006, CR06 tenutosi a Prague nel 10 July 2006 through 12 July 2006. - WIT TRANSACTIONS ON THE BUILT ENVIRONMENT. [10.2495/cr060881].
Effect of the distribution of the arrivals and of the intermodal unit sizes on the transit time through freight terminals
MALAVASI, Gabriele;A. Quattrini;RICCI, Stefano
2006
Abstract
The railway freight terminals play a key role within the multimodal logistic chain. Therefore, the transit time through these terminals represents one of the most relevant terminal performances and at the same time a key component of the freight transport generalized cost, so that its quantitative analysis is a strategic activity, both in the terminal planning (for the existing and for the future terminal) and in the logistic chain organization. The transit time is composed of deterministic and stochastic components, which increases significantly the problem complexity. The authors developed an original model based on queuing theory allowing the calculation of the transit time for a large variety of terminals. Some pilot applications of the model showed that the arrival distributions of both classes of vehicles are critical inputs for the effectiveness of the results. In this framework the present paper focuses on the theoretical study of these distributions including an extended validation campaign based on data available for an Italian case study (intermodal terminal of Pomezia near Rome). Another relevant aspect, affecting the quality of the model results, is the presence in the terminal of different sizes of intermodal units. In the paper a methodology to take into account these size differences effectively is also explained.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.