NS tests new maintenance planning and fixed train formations to improve capacity

Dutch rail operator Nederlandse Spoorwegen (NS) is introducing a series of operational changes aimed at improving train availability on busy commuter days and reducing the risk of overcrowded services during disruptions.

The measures follow a successful pilot project that altered the way routine maintenance is scheduled and are now being complemented by a month-long trial with fixed train formations, Martijn van Vulpen reports. 

Maintenance moved away from busiest days

NS recently tested a ‘smart maintenance planning’ approach at several service depots. The key change was that small, non-urgent repairs were no longer carried out on Tuesdays and Thursdays, which have become the busiest commuter days since working from home became widespread.

Instead, minor repairs, such as damaged seat upholstery or faulty passenger information screens,  are now scheduled on quieter weekdays such as Monday, Wednesday or Friday, or during weekends. Each maintenance report is assessed individually to determine whether the issue can safely wait.

Critical faults, such as failures of air-conditioning systems during warm weather, continue to be repaired immediately.

According to NS, the pilot produced positive results. By shifting non-essential repairs away from peak commuting days, the company can keep more trains available for service. As fewer standby trains are needed to maintain the timetable, operating costs can also be reduced without increasing crowding on board.

The results have prompted NS to expand the maintenance strategy to additional depots across the network.

The approach also affects the future of the ageing ICMm Koploper intercity trains, which can now be withdrawn from regular service earlier than planned. The trains will remain available for the time being as an emergency reserve.

Month-long trial with fixed train formations

Alongside the maintenance changes, NS is running a new experiment with train length and composition.

Between 9 March and 5 April 2026, the operator will run trains in largely fixed formations on many routes across the network. The aim is to reduce the number of unexpectedly overcrowded services during disruptions.

In recent years, the Dutch rail network has faced an increase in operational disruptions as well as significantly more planned infrastructure works. When disturbances occur, the carefully planned circulation of rolling stock can quickly break down, resulting in trains that are either overcrowded or unusually empty.

During the trial, NS will adjust the balance between short and long trains. Some longer trains will be slightly shortened,  for example from ten to eight carriages, while shorter trains will be lengthened, such as from six to eight carriages. The goal is to create a more uniform train length that reduces the chance that a service becomes severely overcrowded when rolling stock has to be reassigned.

Rolling stock of the same length will also be grouped into separate operating diagrams where possible. For instance, three-carriage ICM intercity train sets will be used on intercity services between Groningen or Leeuwarden and Schiphol Airport, while four-car sets will operate on routes such as Groningen–The Hague and Amsterdam–Amersfoort/Deventer.

Similarly, four-car VIRM double‑deck train units will operate on services including Alkmaar–Maastricht and Dordrecht–Schiphol–Venlo, while six-car sets will be deployed on other intercity diagrams. Sprinter trains of equal length will also be grouped into the same rotations.

NS expects the trial to show whether more standardised train lengths can make operations more resilient during disruptions while maintaining adequate capacity for passengers.