Begun this month, the project will continue until mid-December on routes in the Bern-Basel-Zurich triangle, SBB spokeswoman Franziska Frey told the ATS news agency, confirming a report from the Schweiz am Sonntag weekly newspaper.
Normally, long-distance trains arriving at major stations wait several minutes to allow passengers from other connecting trains to board.
Analyses have shown that if a train does not have to wait for a connecting one that is late punctuality throughout the network improves, Frey is quoted as saying.
If a train has to wait for a connection there are relatively few passengers who benefit from being able to switch trains, she said.
“But for numerous passengers already in the train , this holdup can lead to new delays and make them miss connections.”
If the pilot project proves to have no beneficial impact the idea will be dropped.
But if it leads to better punctuality, SBB will determine in 2016 how much time a train can wait in a station for connections, Frey said.
However, the proposal has already come under fire from Pro Bahn Schweiz, the train users' lobby group.
The “zero tolerance” plan for delayed connecting trains would unnecessarily penalize passengers counting on making connections, the group said.
These passengers might be in a minority but if the plan proceeds beyond the test stage it would mean that all trips with connections would be delayed by around half an hour, Pro Bahn said.
The group urged SBB to continue to make trains on major routes to wait a few minutes if a connection is late.