Cost-benefit analysis is often used in appraisal of rail infrastructure investments. A corresponding decision support is, however, not available for rail infrastructure maintenance and renewal. To for example decide whether to renew or continue to maintain an infrastructure asset, a relationship between cumulative traffic and infrastructure failures is required. This relationship is established in this paper, using an empirical (top-down) approach on Swedish data for years 2003 to 2016. It is shown that the average elasticity for track failures with respect to cumulative tonnes is 0.32, and that the elasticity varies for different levels of traffic and for different infrastructure characteristics. The results in this paper can for example be used to calculate the impact cumulative tonnes have on train delay costs, which together with a relationship between cumulative traffic and infrastructure maintenance costs are essential in an economic optimization of maintenance and renewal activities.