New railway legislation in Sweden has increased the need for transparent access charges on the Swedish railway network. We estimate cost functions for infrastructure operation, maintenance and renewal in the Swedish national railway network, using unobserved random effects models and calculate marginal costs for railway infrastructure wear and tear. We find evidence of unobserved effects at a track district level for infrastructure operation, maintenance and renewal costs. We estimate the marginal infrastructure operation cost to SEK 0.50 per train kilometre and the marginal maintenance cost to SEK 0.0029 per gross tonne kilometre. Combining maintenance and renewal cost increases the estimate to SEK 0.0065 per gross tonne kilometre. Altogether, the results indicate that the fees for wear and tear currently in use in Sweden are below marginal cost.