Sydney tram halts CBD traffic due to power glitch

Sydney's light rail testing has hit another bump in the tracks, with a tram failing at the exact same spot it did two weeks ago during testing.

The power to the tram was cut while it was crossing the busy Sydney CBD intersection of George Street and Market Street, causing it to block traffic in the process.

NSW Police were brought in to direct traffic around the tram as crews worked for 40 minutes to free the stuck carriage.

It's the second failure to occur at the same spot in two weeks.

Passengers could be using Sydney's new Light Rail network as early as December 19 as the Berejiklian Government rushes to have the project operational before Christmas.

Light Rail promotional materials say the 12km light rail route will feature 19 stops and extend from Circular Quay in the CBD to Randwick in Sydney's east.

"Civil construction is complete, and tram testing along the alignment is well underway," the government has told commuters.

"Sydney Light Rail plays a key role in enabling Sydney's transport future by transporting thousands of customers between Sydney's Inner West suburbs and Central, and between the CBD and Randwick or Kingsford in the South Eastern suburbs."

The project includes over 24,500 metres of track, including six kilometres of tram lines in the CBD alone.