We have doing lots of research for tour trip in September. After looking at multiple options we have decided to purchase the Half Fare Card for all of our train, tram, and cog rail trips. Do we need to buy any of these train tickets in advance?( I have purchased tickets for a train trip to Italy following our time in Switzerland as buying in advance saved us money). We will be traveling from Zurich to Wengen for a 2 week stay. That means train travel from Zurich, through Bern, Interlaken, and Lauterbrunnen then to Wengen. We will also travel to Zermatt from Wengen at the end of our 2 weeks in Wengen. While in Wengen we will do various day trips using trains. The main question is do we need to buy the tickets in advance from Zurich to Wengen? Do we buy the Half Fare Card from home or from a train station once we arrive in Zurich? Thank so much for your advice!