An Urban-Scale Application of the Problem of Designing Green Tourist Trips with Time Windows

In this paper, we deal with the problem of designing tourist trips with time windows. The proposed optimization model is characterized by the presence of three different objectives: 1) the minimization of transportation costs and expense incurred to access the tourist sites to be visited; 2) the minimization of \(\text {CO}_{2}\) emissions generated by the vehicles used for travel; and 3) the maximization of the attractiveness of the tourist sites to be visited, where the attractiveness of each site is measured qualitatively through a predefined index on a homogeneous scale of values. The constraints of the problem concern, among others, the need to comply with predefined time windows for visiting tourist sites and the maximum total time available for the tourist trips. For each tourist trip, it is also possible to differentiate the tourist sites to be visited belonging to different categories and also provide for the possibility of a lunch break. The proposed model has been applied to a real case concerning the city of Florence, Italy. The results obtained demonstrate the correctness of the model and allow, in particular, to assess the impact of the objective of attractiveness of POIs to visit compared to the other two proposed.