Had the V/Line train not reached NSW by 4pm those aboard would have been required to undergo one week of mandatory isolation.

Kate Martin returned with her daughter Chloe, 37, after needing to cut her four-day visit short to one day.

Chloe lives in Melbourne, but due to a heart condition she opted to return with her mother.

"It's very much old hat for all of Melbourne, I felt sorry for everyone when I was leaving today because you could see nobody was looking forward to it and it's not something we enjoy," she said.

"There was rumblings in Melbourne and having known the language we knew what was coming, so most people had already left yesterday. Hopefully a snap lockdown will be everything we need."

Mrs Martin believed the action may boost vaccination, but that a better national rollout was still needed.

"I think it's been a disaster, the federal government have stuffed it all up," she said.

A Melbourne university student Kaitlin, who declined to give her surname, was travelling back across the border in order to get home to her family in Sydney.

"I'd just come as far as Albury, so then at least I'm out of the state," she said.

"The train was supposed to get in at 3.55 and people were talking about 4pm being the cutoff to get in, so it was a little bit scary because we didn't know why we were delayed."

Kaitlin had only just moved to Melbourne and said leaving so soon due to a lockdown was frustrating.

A passenger from northern NSW, who didn't wish to be named, expressed her frustration at the snap lockdown.

"This is the umpteenth time this has happened to me, we were locked up in Darwin coming home from East Timor," she said.