As of on Wednesday morning, southbound traffic will be backed up 4 kilometres at the entry to the Gotthard, traffic information service Viasuisse reports.
By 3pm, the queue will increase in length to 10km, meaning a waiting time of around 90 minutes.
A Viasuisse map showing zones of heavy traffic (marked red)
Thursday will also see heavy southbound traffic at the Gotthard with the period from 9am to 2pm set to be busiest. After 6pm, the going will be much smoother.
For people heading home after the weekend, you can expect a quite long wait on Saturday from 1pm to 6pm.
But Sunday will be the worst day traffic-wise with a wait of well over two hours for the Gotthard from 11am to 10pm. Traffic will be especially because the Dutch holiday season is also coming to an end.
For those wanting to avoid the Gotthard, Viasuisse advises people from Zurich, Basel and eastern Switzerland use the San Bernardino Route. Other travellers may want to consider the Lötschberg or Simplon pass.