The Measurement of Returns to Density and Scale for Heterogeneous Rail Infrastructure Technologies Estimates for High-speed, Urban, and Classic-regional Lines in France

This paper uti lises a unique data set to study the scale and den sity prop er ties of rail infra struc ture main te-nance, distinguishing between dif fer ent tech nol o gies existing within national rail systems; namely, urban, high-speed, and regional lines. We find dif fer ences in the posi tion and shapes of the alter na tive tech nol o gies, with returns to scale and den sity prop er ties vary ing by net work type. Such tech nol ogy-disaggregated cost struc ture char ac ter is tics have not pre vi ously been derived in the literature, and have impli ca tions for track access charges and rail way main te nance orga ni sa tion. Additionally, the widely used translog func tional form is shown to be insuf fi ciently flex i ble to deal with the dif fer ent tech nol o gies under con sid er ation.