Stroller on departures with seat reservations
You may bring a stroller aboard free of charge. On train departures allowing seat reservations, you must book it as an add-on at Entur, in order to guarantee space on the train. Otherwise, there is no certainty that there will be any space aboard for your stroller.
When there are no seat reservations
On departures without seat reservation, you may also bring a stroller as long as there is enough space aboard. You must check with the conductor upon boarding as the assigned spaces for strollers are limited. As this is a matter of on-board safety, it is always up to the conductor to decide whether or not you may board the train with it.
Traveling with children?
You might want to take a look at some practical information on traveling aboard with children here.