The most popular way to travel to Norway by freight ferry in a van or lorry offers regular sailings and a level of flexibility.
First you catch a ferry from Dover to Calais. Dover to Calais with DFDS sails 10 times a day, takes 90 minutes and is an open ticket so you can turn up and travel on the next available. Then, from there you drive up through Germany and Denmark to Hirtshals in northern Denmark. From here ferries run twice a day to Kristiansand. Kristiansand is about 320km from Oslo or 460km from Bergen.
The only direct freight ferry route from the UK to Norway runs from Immingham to Brevik with DFDS Seaways. Former routes from Newcastle to Stavanger no longer operate. Sailings from Immingham to Norway go twice a week and take up to 36 hours. Brevik is around 160km from Oslo so this route involves the least amount of driving mileage and is ideal for artics, with the opportunity for a rest break on-board, or for unaccompanied trailers.
This ferry can be the most expensive, but on-board facilities are excellent.
You can also sail to Norway from Denmark and Germany but there are a few options.
This includes the Hirtshals to Larvik freight ferry or from Fredrikshavn in Denmark direct to Oslo. Larvik is a better option than Kristiansand if you are going to Oslo as it is only around 130km away.
You can also go from Kiel in Germany to Oslo to cut out some driving times and get a longer break on board the ferry. Any of these ferries are perfect to be combined with a Dover to Calais, Dover to Dunkirk or Folkestone to Calais ticket.
They all will cut out some driving miles and allow you to get a break on board.