PUBLIC TRANSPORT TRAVEL PLANNING APPLICATION MARISOL CORREIA Escola Superior de Gestão, Hotelaria e Turismo da Universidade do Algarve, Campus da Penha, 8000 Faro, Portugal, mcorreia@ualg.pt Key words: Database Application, Relational Database, Transports Planning Abstract: Here it is presented an application that plans out travel on public transports and that chooses the best ones, according to preference criteria provided by the user. These criteria are: the time spent on the travel, the price of the tickets and the quality of the transports. The application combines different means of transport. Algorithms and heuristics were developed to draw up transport plans and to choose the best ones. The best plans are determined using the multi-attributes decision techniques. The application uses a database that was developed in a Relational Database Management System. To draw the database at the conceptual and the applicational level, it was used one of the models based on the object, the Entity-Relationship Model. 1. INTRODUCTION This paper presents an application that draws up transport plans using public transports and shows the best plans, according to preference criteria provided by the user. The application combines different means of transport and can be used at transport terminals (airports, bus and railway stations), at travel agencies or at information posts. For people today, time is an indispensable resource that justifies the planning of some activities, such as travels. Travelling is still a necessity, although the sprouting of information technologies has decreased this necessity. On the other hand, an improvement in the public transports and in the transport infrastructures has been acknowledged in the latest years, leading to a growth in the use of public transports. These are some of the reasons that justify the development of an application of this kind. In order to draw up transport plans, the user has to give information about departure and arrival places. Date and time after which the user intends to leave or date and time, before which the user wants to arrive, are data that also have to be indicated. The user must also specify his/her preference criteria in the choosing of the best plans. The user's choice reflects the importance given to the cost of the travel, the travel spending time, and the quality of the transports. The first approach to the question in study was to represent the knowledge acquired about the public transports, using one of the methods that better represents the problem. In this case, it would not be necessary to represent the knowledge but only the information. However, this is necessary in order to develop a Knowledge-based System (usually called Expert System), for further investigation. A database was developed in a Relational Database Management System (RDBMS). Algorithms and heuristics were developed to draw up transport plans and to determine the best ones. The best plans are determined