The purpose of this study has been the develop of a model for designing an efficient parking pricing policy. The aim is an\ud intelligent control and management system of parking pricing integrated with a redefinition of the circulation scheme for a\ud limited traffic zone in the Central Business District (CBD) of Palermo.\ud The transport demand over the entire area of the town has been studied in order to design various parking pricing scenarios with\ud the application of an additional cost on parking inside the selected area of the CBD. This area attracts most of the private\ud vehicular traffic and it is characterized by university faculties, schools, hospitals, offices and commercial areas.\ud The optimal hourly toll is defined by an iterative maximization process of an objective function. This objective function is\ud subject to the following constraint: the percentage of available parking in the various parking zones has to remain major of the\ud 30%. In this way, the users who need to park close to their final destination can easily find parking. Otherwise it is possible to\ud leave the private car in a “park and ride” area and taking a shuttle bus directed towards the zones of the CBD.\ud A basic principle of this pricing policy is the re-use of revenues for two purposes: to design a shuttle bus service that connects the\ud various “park and ride” areas to the CBD and to improve the local public transport service on the OD pairs that show high travel\ud demand. At the same time it is necessary to eliminate the stop and go flow in cordon roads to increase the capacity and avoid\ud congestion in these critical links.\ud The method shows that in a very simple, and relatively fast, way is possible to get a proposal for the modification of the parking\ud pricing scheme that makes the city center no longer stifled by private car traffic

This research aims to explore the impact of latent variables, mirroring the users' preferences, on the individual decision making process regarding the mode of transport. The paper describes the first results of an ongoing research activity, which derives from a pilot study carried out in Palermo. The authors have administered to a sample of travellers a questionnaire and they simulated the mode choice behaviour referring to the random utility theory. Then the transport demand over the entire area of Palermo has been studied in order to design the cordon pricing scenario with the application of an additional cost on private car dedicated to a selected area of the historic centre of Palermo. The results support the assumption that the design of a competitive public transport supply, using a road pricing policy, should pass through the complete understanding of the relationship between mode choice and latent constructs.

Our research aims to explore the impact of latent variables, mirroring urban travellers' attitudes and perceptions, on the individual decision making process regarding the mode of transport. The paper describes the first results of an ongoing research activity, which derive from a pilot study conducted in Palermo, the capital of the Sicilian Region (in the south of Italy), and demonstrate that policy makers, in designing a socially desirable and environmentally sustainable urban mobility system, should take into account how travellers perceive the qualitative dimensions of transport.