Capacity of railway tracks is a scarce commodity that by nature is more complex than many other commodities. The paper presents results from a series of economic testbed experiments on the performance of different auctioning mechanisms for allocating track capacity between competing users. relevantThe auction mechanism will not only decide a price, it also serves to define the commodities (the particular departure-arrival time slots) that are demanded and selects which of these that are sold. Four combinations of pricing and stopping rules are compared. Realised allocations are very efficient for all four and also generate approximately equal revenue. The research provides input to the process of re-regulating an industry undergoing profound institutional change.