Transport Minister Chris Steel says a light rail route to Belconnen via the University of Canberra will be considered in stage three.

Improvements in the transport network between Wollongong and Sydney are "vital", according to an Illawarra Business Chamber government submission.

Cr Moore said if changes weren't made it would be a bittersweet outcome.

The COVID-19 pandemic has seen a massive fall in the number of train trips made on the South Coast line.