8889 posts
Hello Maureen,
Looks like there is a substitute bus for part of the route (Luzern – Alpnachstad) that day. See attached.
It is not really necessary but you could reserve seat from Alpnachstad to Interlaken.
72625 posts
Watch out for predictive text! Interlaced = Interlaken I presume.
The Luzern – Interlaken Express is the Brünig Pass railway operated by Zentralbahn (ZB). There is no need to waste effort on reservations. The trains run every hour throughout the day. Reservations are not necessary on the Swiss inter-city rail network, which is designed as a regular interval walk on service.
However…
The Brünig pass railway is closed for engineering work between Luzern and Alpnachstad 18 March – 14 April inclusive. There will be replacement buses running.