The development of Canberra's 12-kilometre light rail line will see $120 million of associated road and utilities works completed within five years.
The $800 million line's full business case, which was released by the ACT government on Friday, includes plans for road formation changes in the city to Gungahlin corridor and $118 million in estimated costs for infrastructure and utilities.
The roadworks will include kerb widening, lane adjustments and intersection modifications to allow for the trams.
The business case forecasts changes to traffic signal phasing, the removal of some right turns, widening of the roadway, lane duplication and changes to some property access.
Existing right turns in Flemington Road at the Mitchell Waste Management Centre and Lysaght Street, as well as Northbourne Avenue, Rudd Street and Bunda Street will remain, with signal controls in place.
New traffic signals will be installed at 10 locations to ensure vehicle movements across the light rail tracks are managed.
Traffic lanes in both directions will have duplications in Flemington Road between Kate Crace Street and Manning Clark Crescent, while two car lanes will be reduced to one southbound in Flemington Road between Lysaght Street and Sandford Street.
One bus lane and one car lane between Sandford Street and the Federal Highway will be reduced to one lane and two car lanes will be reduced to one northbound in Flemington Road between Randwick Road and Lysaght Street.
The business case and at least one private consortium expected to bid for the contract consider Walter Burley Griffin's provision of wide median strips in Canberra as a cost-saving advantage compared with other light rail projects, including the Gold Coast.
Other spending detailed in the business case includes $11 million for tram stops and terminus precincts; $137 million for tram signalling and $59 million for a depot in Mitchell.
The document shows Canberra will eschew a "cutting-edge" depot similar to the Gold Coast light rail project, and instead opt for "a modest depot facility".
Other road and infrastructure spending is expected.
"Excluded from the cost estimate are works outside the project's current scope, including park and ride facilities already contemplated by [the] ACT government, and bus interchange works or other roadworks which may be beneficial to the project," the document says.
About 13,400 Canberrans live and work along the tram line corridor, and more than 70 per cent travel to work between Macarthur Avenue and the city everyday.
Canberra retains the highest per capita use of cars of any Australian city, and just 11 per cent of the city's residents use public transport.
The business case estimates 16 kilometres of roads in the light rail catchment area experience significant congestion by cars, leading to a travel time from Gungahlin of between 35 minutes and 45 minutes in the morning peak.
It is estimated that without tram services or other remedial actions to limit congestion, travel time in 2031 could reach 57 minutes from Gungahlin to the city.
With the tram line in place, the average car journey in the same year is estimated to be 42 minutes at peak and tram passengers will reach the city in 25 minutes.
The Liberal Opposition has yet to outline its alternative public transport policy but has forecast improvements to ACTION bus services.
Opposition transport spokesman Alistair Coe said on Friday that light rail could be appropriate for Canberra in the future but the current proposal did not represent value for money.
Expressions of interest in stage one of what could become a city-wide network have opened for private sector expressions of interest, with the government's closing deadline set for December 19.