Cost functions for rural and mixed footpaths

In the context of transport studies, sustainable mobility is increasingly occupying an important space. Sustainability is not only a principle to be pursued by reducing the impacts of vehicle travel, but an important result to be achieved by promoting healthy lifestyles based on active mobility, i.e. walking and cycling. This applies both to "compulsory" mobility, i.e. for travel due to professional or study reasons, but also for leisure or tourist mobility. This paper focuses on active mobility for tourism and, in particular, on pedestrian itineraries in the extra-urban area. An innovative approach aimed at determining cost functions to qualify hiking-type routes is proposed. The outcome of the research allows to highlight the specific characteristics that lead to differentiating the cost functions in pedestrian mobility for tourism reasons from the traditional functions. Furthermore, a specific investigation methodology is introduced which should allow to arrive at the determination of mathematical models, calibrated on a statistical basis starting from the specified cost functions. This represents the fundamental basis in terms of mathematical modelling on which subsequent simulations can be based. Indeed, the introduction of any digital innovation or simulation model in the analysis of active mobility cannot be separated from an upstream analysis of the pedestrian mobility models as well as their calibration. Walking is the simplest human activity but no less important in terms of impact on the challenges of Agenda 2030 that the States are facing with great determination.