The Nederlandse Spoorwegen (NS) will significantly increase its train services starting December 15, introducing more frequent services during peak hours, evenings, and weekends. This is described as the largest schedule change in years, aiming for service levels surpassing those of 2019. New ‘quarter hour services’ will operate between major stations, although issues with the high-speed line (HSL) persist, causing service disruptions and delays due to prior construction errors and new train deliveries.