Yes, the Viva Viagem card is the primary contactless smart card used for public transportation in Lisbon, and it is fully valid on all of the city's iconic yellow trams, including the famous historic Route 28 and the modern Route 15 to Belém. This card is highly recommended for travelers because it offers a much lower fare compared to buying a "paper ticket" directly from the tram driver or onboard machine. You can load the card with individual trips, a 24-hour pass, or "zapping" credit (a pay-as-you-go balance). When boarding the tram, you simply tap the card against the yellow card reader located near the entrance. It is also valid on the city's funiculars, the Santa Justa Lift, the metro, and even suburban trains to Sintra or Cascais. Keep in mind that each traveler must have their own individual Viva card, as you cannot "swipe" twice for multiple people on the same reader.