In this paper, we combine engineering and economic methods to estimate the relative maintenance cost of different types of damage on the Swedish rail infrastructure. The engineering method is good at predicting damage from traffic, while the economic method is suitable for establishing a relationship between damage and cost. We exploit the best features of both methods in a two-stage approach and demonstrate its applicability for rail infrastructure charging, based on a sample of 143 track sections comprising about 11,000 km of track. The paper implements for the first time the method previously proposed in Smith et al., whilst also enhancing the method in several respects. We demonstrate how the estimated relative maintenance costs related to different damage mechanisms can be used to calculate the marginal cost of different vehicle types. The results are relevant for infrastructure managers in Europe who wish to differentiate their track access charges such that each vehicle pays its short run-marginal damage cost, which can support more efficient use of the rail infrastructure and influence vehicle design to minimize system costs.