Additional staff will be on hand when large crowds are expected to board the trams from 11am on Saturday.

There'll be no fares charged during the opening weekend of the $2.9 billion project which has been plagued by cost blow-outs and significant delays.

The branch line to Kingsford isn't expected to open until early 2020.

NSW Transport Minister Andrew Constance says Saturday will be an exciting moment for the city.

"Everyone's ready to go. Please get out and enjoy the light rail this weekend," he told reporters on Friday as he opened a new pedestrian footbridge over Anzac Parade at Moore Park.

Mr Constance urged passengers to be patient and motorists and pedestrians to remain vigilant.

"We just need people to be mindful that the trams will now be carrying people," he said.

"If people could just be patient, there will be large crowds, we know that. We've got a race day on, we've got shopping in the city, it's going to be busy."

The minister has previously warned people to "use their brain" particularly when using mobile phones and wandering near trams in the CBD.

Transport for NSW co-ordinator general Marg Prendergast says authorities will learn from any issues in the first months of operation.

"We know that the first six months is going to be difficult," she told reporters.

"We know stuff is going to happen. What we need to do is respond really quickly when an incident occurs and learn from that incident."

A few hundred staff will be on deck this weekend while extra buses will be running from Randwick into the city.

Traffic controllers and police officers will be on the ground to deal with higher than normal volumes of people, Ms Prendergast said.

A coupled tram holds up to 450 passengers, the equivalent of nine buses.

Some 200,000 kilometres of tram testing has already taken place while the 100 drivers have each undertaken 190 hours of training.

The new network will move up to 13,500 commuters an hour during peak time in both directions, the state government says.

Australian Associated Press