Transit
  traffic
You can see here how many net tons have crossed the swiss alps since 1.1.1999.

 

 
Since the beginning of 1999 Nt (net tons) goods have crossed the swiss alps.

Nt of them were on the road
and Nt crossed the alps on the rail.

The Gotthard is the most used passage. Nt have crossed it or went through it since 1.1.1999.
The numbers are estimations from 1997 data. They base on the "Zahlenspiegel der Schweiz 1999" edited by the "Gesellschaft zur Förderung der schweizerischen Wirtschaft (wf)". Original source: Federal Office of Statistics, Switzerland. Original source: Federal Office of Statistic, "Schweizer Verkehrsstatistik".