2.3 Planning support systems The methods and tools for estimating cycling potential outlined in Table 1 were generally created with only a single study region in mind. The benefit of this is that they can respond context-specific to practitioner and policy needs. However, the PCT aims to provide a generalisable and scalable tool, in the tradition of Planning Support Systems (PSS). PSS were developed to encourage evidence-based policy in land-use planning (Klosterman, 1999). The application of PSS to transport planning has been more recent, with a goal of “systematically [introducing] relevant (spatial) information to a specific process of related planning actions” (Brömmelstroet and Bertolini, 2008). The PCT is systematic in its use of national data for all parts of the study region (in this case England) and relates to a specific planning process — the creation of new and enhancement of existing cycle infrastructure. PSS typically work by presenting evidence about the characteristics and needs of the study region in an interactive map. A central objective is to visualise alternative scenarios of change, and explore their potential impacts. The results of traditional scenario-based models are usually not locally specific (Lovelace et al., 2011; McCollum and Yang, 2009; Woodcock et al., 2009). Online PSS can overcome this issue by using interactive maps (Pettit et al., 2013). The emergence of libraries for web mapping (Haklay et al., 2008) has facilitated online PSS, offering the potential for public access to the planning process. Transparency is further enhanced by making PSS open source, in-line with a growing trend in transport modelling (Borning et al., 2008; Novosel et al., 2015; Tamminga et al., 2012). In these ways, PSS can make evidence for transport planning more widely available, and tackle the issue that transport models are often seen as ‘black boxes’, closed to public scrutiny (Golub et al., 2013). With reference to a publicly accessible online map-based PSS for strategic land use (and to a lesser extent transport) planning, Kahila-Tani et al. (2016) provide guidance on the wider public participation process: it should be transparent , influence real world decisions, 8