Quick, but not dirty: The role of quick scan tools in traffic and transport research

Policy makers, from small municipalities to (inter)national government agencies, consult transport models output in order to enrich their decision-making process with as much information as possible. This makes the demand for specific and promptly available modelling data often bigger than actually can be met within the available personnel or budget. For this reason, quick scan tools are used in various stages of policy making. These tools shortcut the modelling process by employing less data, less calibration and less theoretically underpinned modelling approaches than proper transport models. Obviously, such tools cannot provide the same detail and quality than full transport models, and are therefore often dismissed in the community of traffic models as negligible at best, but most often are characterized as misleading and harmful to the decision-making process if applied beyond their scope.

However, the need for these tools is high and they are used in practice despite their reputation. Quick scan tools therefore can play an important role in the decisionmaking process. However, so far the quality of such tools and their role in the process of evaluating transport policy schemes is a topic that has gained little to no attention in the scientific community researching transport models. By rejecting the whole concept of quick scan tools, the chance has been missed to actually assess such tools with the necessary (scientific) scrutiny, in order to ensure that they are in the best shape they can be. As a result, at the moment, there is no common understanding on what these tools are or should be, what the minimum quality standards of such tools should be, and how they should be used in the different phases of transport planning.

This paper aims to discuss the pros and cons when it comes to working with quick scan tools, in the hope to kick-start a broader discussion about how to employ such tools in the best way possible. We discuss the challenges that come with making a tool that supports its users to perform meaningful analyses while limiting the possible interactions with the data/tool to an acceptable minimum. We address these issues by describing the design principles and procedural arrangements we apply to the quick scan tool owned by the Dutch Ministry of Infrastructure and Water Management, the ‘Mobiliteitsscan’ (Mobility Scan).