Using observed costs for operation and maintenance of the Swedish national road network, together with information about the amount of traffic and a description about the road network for the period 2004–2009 cost functions are estimated. From these functions cost elasticity is derived and marginal costs are computed. The results of the estimations from these years are in this study compared to analyses of a similar but older dataset covering the years 1998–2002. The results are reasonably consistent in some cases while in other cases differences are found between the two datasets. Given the limited amount of empirical results about these issues, the differences are not strikingly large. No obvious contradictions between analyses based on the older and newer dataset are found. Our view is that results from the two datasets in some sense confirm each other, although more data is required to establish more precise estimates of cost elasticity and marginal costs. From the analyses performed in this study the marginal costs can be estimated within an interval corresponding to 5–30 percent of the average costs.
Our estimates show that marginal costs for operation and maintenance of the national road network are lower than the average costs (all elasticity is in the range 0.31–0.85). The cost increase in paved road maintenance resulting from an extra truck kilometer is about
0.21–0.32 Swedish crowns. For gravel roads the corresponding marginal cost is about
1.65–2.72 Swedish crowns. For operation measures the marginal cost is 0 Swedish crowns on paved roads and 0.15–0.24 Swedish crowns per vehicle kilometer on gravel roads. The per vehicle kilometer cost for winter maintenance is estimated to 0.01–0.02 Swedish crowns.