Globally, transport systems help bridge distances in time and space and play a central role in securing accessibility for people and businesses. However, this is not without negative consequences such as investment costs, congestion, noise and barriers in the urban fabric. Consequently, active planning that limits negative consequences and enables a shift towards sustainable modes of transport is necessary to steer developments in an appropriate direction (Banister, 2011; Koglin and Rye, 2014). In order to gain an idea of whether planning is, in fact, steering development in an appropriate direction and to identify cost-effective objects, tools and models help analyse the proposed transport policies. Most commonly, the tools aim to estimate user-benefits in terms of accessibility (Laird and Venables, 2017), although there is an increasing interest among planners in tools that capture softer aspects of a social nature (Johansson et al., 2017). In recent years, infrastructure and traffic have come to be seen as more than just transport solutions (Isaksson et al., 2017), which opens up for a range of appraisal tools. In Table 1, we separate between two categories of ex-ante appraisal tools. Firstly, decision-making tools include cost-benefit analysis (CBA) and multi-criteria analysis (MCA). The purpose of decision-making tools is to provide the decision-maker with a comprehensive picture of a policy. Secondly, impact assessments (IA) are tools such as transport system analysis (TSA) and social impact assessment (SIA). IA analyse consequences of policies and can be an integral part of decision-making tools (common for the TSA), or a separate report (common for the environmental impact assessment (EIA)). Previous research on the CBA concerns its development (Eliasson, 2009; Börjesson et al., 2014; Laird and Venables, 2017), its role in public policy-making (Hahn and Tetlock, 2008; Mouter et al., 2013; Mackie et al., 2014; Andersson, 2018) and its limitations (Sen, 2000; Næss, 2006; Damart and Roy, 2009; van Wee, 2012). This article positions itself in the CBAs role in policy-making and its limitations. We are not going to discuss the MCA at length, but there is research on tool development (de Brucker et al., 1995; Macharis et al., 2008; Thomopoulos et al., 2009) and tool application (Macharis and Bernardini, 2015). The qualitative feature of the MCA makes it able to include input from an SIA. SIA, as it is understood in this paper, has its roots in sociology and other social sciences with the purpose of predicting consequences in terms of, for instance, equity across groups of people as an effect of a policy (Esteves et al., 2012). This paper is about the planning and ex-ante appraisal of a public transport investment in Sweden. The aim with this paper is to elaborate on the use of appraisal tools, i.e. the kinds of tools employed and at what stage they enter the planning process. In addition, the aim is to discuss where there might be scope for improvement of CBA and the TSA. This is done by looking at a light rail project in Stockholm, where we study planning documentation and do interviews with persons involved in the planning process. The research questions are: What is the role of appraisal methods in this project and how concordant are they with the planning procedure? Can the appraisal methods be improved, and if so, in what aspects?
