Planning and decision making on spatial issues is a complex process which deals with a large number of variables, interests and stakeholders. Interactive visualisation tools can help, enabling information to be shared using spatial data visualisation, also known as ‘geo-visualisation’. The idea is that interacting with data can improve users' knowledge and visualisation can increase intuitive perception, making them better equipped to evaluate alternative development options. The visual system presented in this paper works in both two and three dimensions, according to users' skills in interpreting images. It has been used in different applications, with diverse purposes and spatial scopes, showing its effectiveness in creating a common language among stakeholders and enabling discussions on spatial development.

This paper describes a visual tool for data analysis applied to a case in public transport. Our tool is based on geo-referenced dynamic maps, created with free Web GIS applications, and allows users to visualize data and interact readily with a large database of public transport service information. This tool will support decision-makers in detecting issues of inefficiency and ineffectiveness related to the public transport services of a given area. The paper focuses on the visualization system, its features, and its use, detailing the indicators utilized and the analyses it may be employed for

Since spatial decision processes have to deal with large number of actors, opinions and interests, literature commonly agrees in recognising data sharing and communication as essential in achieving decisional tasks (Van den Brink et al., 2007; MacEachren et al., 2004). The following chapter describes a methodological instrument for managing data, namely the Interactive Visualisation Tool (InViTo). InViTo aims at supporting spatial decision-making processes by proposing a framework for data knowledge. Principally based on Grasshopper, a free plug-in for McNeel's Rhinoceros, InViTo combines GIS data with CAD drawings and raster images for generating interactive spatial visualisations. It is conceived to display in real time the relationships between the territory and planning choices; thus, it is particularly indicated for stimulating discussions and sharing information in collaborative processes. Its high flexibility allows its use in different case studies with a variety of purposes and scales. Innovative elements in approaching spatial decision processes are discussed.

Multiple Criteria Decision Analysis (MCDA) is generally used to support planning and decision making processes, but the sharing of information is often limited by two main factors. First, many users have difficulty reading output data, especially tables, matrixes or databases. Second, the presence of many actors introduces different disciplines, knowledge, interests and languages. This paper shows the contribution that the visualization of spatial data can give to the Analytic Network Process (ANP) (Saaty, 2005; 2001; Saaty, Vargas, 2006). This study aims to use visualization techniques to create a common grammar among actors involved, and a shared basis for generating discussion. To do this we have implemented on-going research on a modelling system which is able to visualize various kinds of data in real time. This modelling system works on generative and parametric features applied to datasets, and is based on McNeel’s “Rhinoceros” software and its free plug-in "Grasshopper". The starting point of the work described here is an application on a German section of Corridor 24, Genoa-Rotterdam, part of an Interreg IVB NEW Project, called “Code24”. The goal of this ANP application is to rank three scenarios of improvement of the "Betuwe" railway line connecting Oberhausen to the Dutch borders. The research resulted in an academic internal application which allowed us to improve the system for use in real-world focus groups which included the main stakeholders of these territorial transformation projects.http://dx.doi.org/10.13033/ijahp.v3i2.109