A $2.1 billion light rail line is going to be established from the CBD to Randwick and Kensington to provide alternatives for passengers.

However, a confidential report prepared by Transport for NSW predicts that commuters are likely to spend nearly nine minutes on the tram at red lights along the journey.

Delays would most likely occur in the southern CBD and Surry Hills as the tram would be waiting for green lights at intersections. Passengers are expected to experience delays during both morning and evening peak hours. Junctions such as Crown and Devonshire streets at Surry Hills or Darley and Alison Roads near Randwick are places where the delays will occur.

Action for Public Transport Secretary Jim Donovan commented that if planning cannot ensure the light rail will have traffic light priority over the other transportation methods, the tram trips would be slow and less comfortable for passengers. He also pointed out that if the delay is not tackled, existing bus lines would be more attractive to passengers considering shorter travel time.

However, prioritising trams at junctions would then increase the travel times for motorists and other road users. Lead transport agency said the needs of the light rail and existing road users must be balanced for an ideal transport network.

The 12-km light rail has suffered criticism from the community for its increased cost, continuous delays and the forced closure of some local businesses due to construction along the route.