Development of railways has always raised new demands. Speeds and loads have increased quite significantly during the history of the railways. For newly constructed lines this has led to the introduction of larger rail profiles with better steel grades, improved rail support in the form of high-performing fastenings, sleepers and ballast layer, and in bridges designed for higher loads and speeds. At the same time the large majority of the railway infrastructure is old and built according to codes and demands of the time of their construction. Very few new railway lines are designed and constructed specifically for freight traffic. The trend today is that the new lines are designed for high-speed operations and that the existing lines are transformed to carry more freight traffic. As mentioned, these existing lines are constructed for traffic demands from the time when they were built. This means that these lines have to be upgraded if they should fulfil the requirements of the new freight operations. Consequently, upgrading has and will be an important future measure to meet current and future demands from industry and society. The big challenge is (and has for a long time been) how to upgrade existing infrastructure in a cost efficient and environmentally friendly manner. In particular this relates to some limitations are not easy to address, as will be outlined below. This deliverable aims to support Infrastructure Managers (IMs) in how to assess their infrastructure with respect to upgraded freight traffic in a methodical manner that ensures a (cost) efficient, safe and environmentally friendly upgrading. Several recent R&D projects have increased knowledge and understanding of track upgrading. Figure E1 in the Executive Summary shows examples of EU-projects carried out during the last 10 years that have provided input to this guideline. The guideline is structured such that after an overview of the objectives in chapter 2, chapter 3 investigates different traffic situations. The consequences of these traffic situations are assessed in focus on how they influence the infrastructure. In chapter 4 the influence of upgrading on the infrastructure is investigated. Recommendations and examples of methods for assessment and analysis of consequences of upgrading are provided. In chapter 5 different maintenance routines are evaluated with respect to consequences resulting from new traffic demands on infrastructure. This guideline is intended to be upgraded to a new version – D1.1.5 – at the end of the Capacity4Rail project. In the upgraded version additional findings from Capacity4Rail, and also parts that were not possible to include due to the limited available budget will be added.