Bagasjetransport - literally luggage transport - is the daily transfer of overnight luggage between lodges by support vehicle on a self-guided active travel trip. The traveler rides or walks each day with a small daypack carrying water, snacks, weather layers and a basic repair kit. The main overnight luggage - full bag, change of clothes, evening kit, anything not needed during the active day - is collected from the morning's lodge and delivered to the evening's lodge by the operator's support vehicle.
The function is mundane but the consequence is large. The difference between cycling 70 kilometers a day with a fully-loaded touring bike and cycling the same distance with an empty daypack is, over a week, very substantial. The same is true for walking 15-20 kilometers a day with a 12-kilo overnight pack versus a 5-kilo daypack. Most international visitors who try the unsupported version once become firm advocates of the supported version after the first day.
How it works in practice: the support vehicle is usually a small van, typically driven by an employee of the local operator. It picks up bagged luggage from the morning's lodge after breakfast (luggage left in the lodge lobby with a tag), drives the day's route, and drops the luggage at the next lodge in time for the evening arrival. On most multi-day routes the same vehicle is also on call for emergency pickup - mechanical breakdown, weather forcing a shorter day, an injury that requires the trip to be reshaped on the fly.
The standard inclusion is one bag per person, with a weight limit (typically 20 kg) and a size limit. Most operators allow a second small bag for a modest additional fee. Bicycles and ski equipment are not transferred - those go with the traveler - but mountain ski-touring trips often include separate arrangements for skis to be moved between huts on the support vehicle when the route allows it. The whole format is invisible when it works correctly, which is the point.