Why will Waterloo and Braine-l’Alleud lose their Brussels trains on Car-Free Sunday?

Infrabel will close the railway between Brussels and Nivelles throughout the weekend of 19 and 20 September, leaving Waterloo and Braine-l’Alleud without direct trains to the capital on Brussels Car-Free Sunday. La Dernière Heure first reported the clash, which affects Line 124 during a weekend when Brussels is explicitly inviting visitors to arrive without a car.

The timing matters well beyond an awkward calendar coincidence. On Sunday 20 September, private motor traffic will be restricted across the Brussels-Capital Region from 09:30 to 19:00, according to visit.brussels. Residents of Walloon Brabant, including commuters, families and international staff working in Brussels, would ordinarily regard the train as the obvious way into the city. Instead, passengers using Waterloo, Braine-l’Alleud and stations farther south must consult SNCB’s journey planner for the replacement arrangements and allow more time. The detailed substitute timetable was not publicly verifiable when this article was prepared.

The closure also coincides with Brussels Heritage Days and the city’s Comic Strip Festival, both scheduled for that weekend. That makes the disruption more than a routine inconvenience: it weakens a central promise of Car-Free Sunday, namely that people can experience the capital without relying on private cars. It also exposes the fragmented organisation of Belgian mobility. Brussels sets the road restrictions and cultural programme; federal companies Infrabel and SNCB manage the railway infrastructure and passenger service; Waterloo and Braine-l’Alleud sit across the regional border in Wallonia.

The competing perspectives are unusually clear. La Dernière Heure described the situation as “surreal”, reflecting the view of passengers and local communities confronted with a sustainable-mobility event that is harder to reach sustainably. Infrabel’s case is structural: the company says the Line 124 works are intended to “facilitate access to and from Brussels” and curb growing car traffic into the capital. The short-term closure is therefore part of a project designed to solve precisely the longer-term problem that the closure aggravates for one weekend.

Line 124 links Brussels with Waterloo, Braine-l’Alleud and Nivelles and forms a major southern branch of the planned Brussels Regional Express Network, or RER. Infrabel says work at Braine-l’Alleud includes completing the Braine-Alliance stop and preparing additional tracks. Its current project information schedules finishing work around Braine-Alliance through December 2026 and broader work at Braine-l’Alleud into 2027. SNCB says Braine-Alliance is due to enter passenger service with its December 2026–2029 transport plan.

This is not the first such collision. RTBF reported that Line 124 was also closed for RER construction during Brussels Car-Free Sunday in September 2021, when replacement buses were arranged between Brussels and Nivelles. The recurrence points to a persistent coordination problem: intensive railway works are easiest to conduct over weekends, while Brussels concentrates several of its most public-facing mobility and cultural events on those same days.

There is no meaningful international or EU-policy dispute here, despite Brussels’ role as the seat of major European institutions. The practical connection is that EU staff, diplomats and other internationally mobile residents living along the Waterloo–Brussels corridor face the same disruption as everyone else. This is Brussels as a city and transport destination, not “Brussels” as shorthand for the European Union.

For travellers, the immediate advice is simple: do not assume the usual Waterloo or Braine-l’Alleud train will run on 19 or 20 September. Check SNCB’s planner shortly before departure, examine any replacement-bus route and verify whether bicycles can be carried. What remains to be seen is whether SNCB and Infrabel provide enough substitute capacity for the additional Car-Free Sunday demand—and whether Belgium’s transport authorities can avoid repeating the same contradiction at future editions.