The new $2.1 billion light rail line 12 kms long will extend from Circular Quay along George Street through Surry Hills to Kingsford and Randwick and is due to be finished in 2019. The document appears to be preparing passengers for tough times ahead: "We are already starting to experience congestion at levels approaching the worst among developed countries. Sydney is more congested than New York – even though we only have half their population." It shows traffic travelling towards the CBD has slowed by 20 per cent over the past two years. "Over the next 20 years demand will grow by 30 per cent, leaving the city in gridlock," the document states. "We cannot simply add more buses to already congested streets."

The guide's comparison stating Sydney congestion is worse than New York came from the Mercer Livability Index. The congestion rating is given as a percentage and is the extra time a journey would take compared to free flowing traffic. Sydney has a congestion rating of 34 per cent, while New York, which has a congestion rating of 26 per cent. Bus drivers on the front line fear they may have to endure abuse from passengers trying to cope with the changes, with one predicting that implementing the changes would be "a nightmare". Gary Way, president of the Rail, Tram and Bus Union, said he hasn't ruled out industrial action "if it doesn't work". "We hope the plans all come together but with such radical changes no one really knows whether it will succeed," he said.

"I am not going to pretend I know how Sydney is going to work without George Street because it is mind-boggling. If it quickly becomes evident that it is unworkable the bus drivers won't put up with it. We are not a punching bag. We will be saying, 'Fix it', or they will have to face industrial issues. We are not frightened to take action." Bus drivers are also concerned about congestion at new terminuses at Gresham Street near Bridge Street with only one bus shelter and at King Street Wharf. They also fear the right turn from York Street into Erskine Street could become even more of a bottleneck than it is now. A public relations campaign will start on Monday to help people plan their trip into the city before the changes start. Co-ordinator general CBD for Transport for NSW Marg Prendergast was upfront about the impact of the bus changes saying there will be "winners and losers". "We expect the first few weeks to be difficult because we need to bed it down. Our motto is 'monitor and adjust'."

New bus lanes, trimming of kerbs and changes to signals to give buses priority would significantly improve the flow of buses, she said. "There will be locations where there could be some bus bunching. We are worried about the terminuses, particularly the new terminuses. But ultimately once we bed it down it is going to provide better reliability because the buses will come, drop on the edges and just leave the city because they are coming in on the outskirts. She said once George Street is removed that is 25 per cent of north-south capacity gone. "What we are investing in to actually break the whole cycle of the city being clogged is investing in light rail which will provide a really good intra-CBD option that's much cleaner, quieter and turn up and go every four minutes. "The bus drivers have got a critical job. We are going to be sending out a really strong message, give them a break. This is the biggest change in bus operations in 30 years. We are not shying away from the fact that the first four weeks could be difficult but just treat the bus drivers with some room and respect."

Key issues passengers face include: • About 330 of more than 700 buses (45 per cent) entering core CBD in the morning peak hour will be removed to reduce congestion • New routes on Elizabeth, Castlereagh, Park, Druitt, Clarence and York streets • Routes terminating outside the city close to other public transport options

• Most to experience timetable changes and some a change to bus route or number Congestion by numbers: An extra 1.6 million living and working in Sydney by 2031 Trips to and from the CBD from 630,000 today to 775,000 by 2031 Trips within CBD 1.26 million today to 1.7 million in 2031

10,000 extra jobs in the CBD over next 20 years Between 8am-9am on weekdays 1000 buses enter CBD Over next 20 years demand to grow by 30 per cent Source: State Transit. NEW YORK, NEW YORK

Population: New York City 8,406,000 (Sydney 3,908,000)

Subway commuters: in 2014 average weekday subway commuters were 5.6 million, the highest since 1949.

New York City Subway opened 1904.

Full fare for both bus and subway is $2.75

Half fare (children, students, etc) is $1.35

Subway lines 24; Bus routes 233 Big yellow taxis in NY: 13,437 Find out more about changes: Call 131 500, Download new timetable: mysydney.nsw.gov.au/news/new-cbd-bus-network

See new bus routes at mysydney.nsw.gov.au/bus#bustool. App: Commuter NSW helps with trip planning.