The main Dutch rail network concession (Hoofdrailnetconcessie) for 2025-2033 was privately awarded to NS (Dutch Railways) at the end of 2023. The question concerns what form market regulation on Dutch rail might take after 2033. The KiM Netherlands Institute for Transport Policy Analysis identifies in this study what we know about the effects of different alternative types of market regulation on the operation of the market for rail passenger transport. This study provides insights into the advantages and disadvantages of different types of market regulation and offers useful guidance on the choices to be made about market regulation on the main Dutch rail network (Hoofdrailnet, HRN) in the future. KiM also aims to contribute to the Future Rail Market Regulation (Toekomstige Marktordening Spoor, TMS) programme of the Dutch Ministry of Infrastructure and Water Management.