Resumo:
The relevance of urban freight transportation has been growing due to the increase in the population which lives in urbanized regions. This fact increases the number of vehicles in urban centers and also the demand for goods, which generates negative externalities such as congestion, emission of pollutants in the air, lack of parking spaces, among others. These problems are present not only in large cities, but also in small and medium-sized cities. Despite this, urban freight transportation is a fundamental factor for urban development, influencing both urban mobility and interactions between society, the environment and commerce. However, freight transportation is often not considered in the planning and regulation of urban transportation, being the main focus on passenger vehicles. These gaps motivated the emergence of City Logistics, a concept that aims to reduce the disorders caused by the transportation of goods while promoting cooperation between the parties involved in this sector. Regarding the understanding of this scope in medium-sized cities, there is still a reduced literature in the national and international scenarios. Thus, the objective of this study is to develop and use freight trip generation models to determine the number of freight trips attracted by commercial establishments in medium-sized cities, with the city of Itajubá-MG as the object of study, quantifying the supply and demand for loading/unloading parking spaces in this region. First, a questionnaire was applied personally at 200 retail establishments to collect statistically reliable data. With these data, freight trip generation models were developed and they estimated that the studied region can receive around 539 daily trips, showing that the 19 existing loading/unloading parking spaces are equivalent to only 34.5% of the 55 parking spaces needed to meet estimated daily trips. Therefore, it was proposed to implement 36 new loading/unloading parking spaces located in areas of greater demand for goods deliveries. It was also found that the greater the distance between loading/unloading parking spaces and areas with a higher concentration of deliveries, the longer the duration that freight vehicles are parked in these parking spaces. This increase may be up to 75.42% for small vehicles (Pickup/Van/Truck), 30.17% for medium vehicles (VUC) and 18.86% for large vehicles (Truck). In addition, the simulation of some scenarios showed how three City Logistics measures can optimize the use of these parking spaces. Compared to the current scenario, freight consolidation (CCU), off-hour delivery (OHD) and staggered delivery (ITS) would reduce demand for parking spaces/hour by 65%, 20% and 8%, respectively. The freight trip generation models developed proved to be effective in quantifying the trips attraction potential of the establishments and also assist in decision-making to solve the problems of urban freight transportation. It was also observed a need for greater integration between local retailers and public authorities for a better functioning of local goods transportation. It is also suggested that local authorities increase inspection over the use of public loading/unloading parking spaces. Finally, the methodology adopted in this work can be used in other medium-sized cities with similar characteristics to those of Itajubá. However, when implementing City Logistics initiatives, attention should be paid to the particularities and adjust these initiatives according to the reality of each city studied.