Light rail on track in Sydney CBD

More than 50 years after tramlines ware shut down in the Sydney CBD, the first 80 metres of the light rail has been laid.

Transport Minister Andrew Constance on Monday said it was an historic moment in Sydney's history as the 80-metre track was cemented in place on George Street in front of Town Hall.

"Building this world-class public transport system down one of Sydney's oldest streets has not been without its challenges, but we're getting on with the job," he said.

Last month an audit revealed that the CBD to eastern suburbs light rail link had cost taxpayers and extra $517 million.

Testing on the $2.1 billion rail link is expected to start by mid-2018, with the full service to open by early 2019.