IMPROVERAIL is a European project launched on July 1st, 2002. Besides several European academic institutes as well as consultants and stakeholders from the Railway industry, the project involves the Swiss Federal Railways, the Swiss Ministry of Transport, SMA-partners, Zürich, and EPFL, Lausanne. The general aim of IMPROVERAIL is to support the establishment of railway infrastructure management in accordance with Directive 91/440 and following, by developing the necessary tools for the modelling of railway infrastructure and access management. First of all, the paper briefly presents the main issues tackled by IMPROVERAIL, highlight-ing their relation to the railways infrastructure management. Then, the paper presents more in depth the work done within the first part of the work package 5 (WP5) of the project, encom-passing three particular topics: • Analysis and rough modelling of long-term infrastructure capacity evolution • Analysis and rough modelling for the assessment of long-term policies regarding in-frastructure maintenance and renewal • Functionality of computer-based decision support system to deal with the long-term dependence between renewal/maintenance and capacity The research results in the conceptualisation of a methodology dealing with the above-mentioned objectives, namely the simultaneous consideration of capacity needs (and invest-ments) and strategic maintenance and renewal policies. In particular, two computer-based tools have been developed. The first tool assesses the capacity of a railway network and esti-mates the value of the capacity, which is related (among other things) to the saturation rate. The second tool simulates long-term policies for railway infrastructure maintenance and re-newal.