Rail Infrastructure Fund (RIF)
The noise abatement programme is a component of the expansion programme for rail infrastructure, which was approved by the Swiss Parliament. The funds used to reduce noise along existing rail routes are fully non-repayable contributions from the Rail Infrastructure Fund (RIF).
This link will take you to further information about the operating principles and the sources of financing for this Fund:
In March 2000 the Swiss Parliament approved an overall credit of CHF 1.854 billion (as of October 1998, not including inflation) for all noise abatement projects in the existing rail network.
The revised law of March 2014 reduced the credit, at the same prices, to CHF 1.515 billion.