Transport Minister Meegan Fitzharris said the only firm decision made about the route from Alinga Street to Woden was that the light rail line would cross the lake on Commonwealth Avenue bridge and end in the Woden town centre. The rest was up for study and feedback.

The work would help the government "define what stage 2 looks like precisely", including the alignment, the number and location of stops, and land development, and would feed into the business case.

"Commonwealth Ave bridge is a certainty, Civic to Woden is a certainty, and today is the start of reaching out to get the experts and the community involved to determine further detail about the stage 2 route," she said.

The government was yet to determine whether it would use State Circle or Capital Circle to round Parliament House.

Asked about a proposal from planner David Flannery, who is also Heritage Council chairman, for the line to make its way through the suburbs of Forrest, Deakin, Hughes and Garran, Ms Fitzharris said the government was open to all such ideas.

"That's an option. We don't think it's the most attractive option for a number of reasons. But we'll certainly be willing to look at all those options and see which one works best for the community, which delivers the benefits ... in terms of transport, in terms of urban renewal, in terms of amenity and in terms of rejuvenating different parts of the route. So it's all in the mix."

Asked about the problem of pedestrian access and commercial development alongside the nationally important routes such as Adelaide Avenue, Ms Fitzharris said. "They are all solvable problems, and they're all issues that present opportunities and challenges, but we're keen to explore those opportunities."

The location of the Woden town centre stop had not been determined, and the government was keen to look at possibilities for access also to Canberra Hospital.

The tender documents say the Woden line "will involve numerous commercial, technical, planning and other challenges. Nevertheless, such challenges must be addressed if the ACT government's vision for a citywide light rail network is to be realised".

Challenges included the need for technical, operational and contractual integration with the Gungahlin line while obtaining value for money, choosing the precise route alignment, "potential staging options", "packaging options", such as including other infrastructure beyond light rail in the work, and the delivery model (whether it would go to the consortium building and operating stage 1 or a new private partner, or be delivered in a different way).

The project also required planning approval from the National Capital Authority, had "potential bridge, tunnel and gradient engineering issues", issues to do with "traffic priorities and journey times", passenger access to stops, and the need for wire-free running, "including length and gradient issues over Lake Burley Griffin".

Tender documents say the proposed corridor is about 10 kilometres long via Deakin and Parliament House, with 10 stops.

The government called on Friday for tenders for work on "evaluating staging options", providing strategy and procurement advice, and developing the business case.

Next week it would call for bids to do technical support, transport modelling and communications, a spokesman said.

Ms Fitzharris said a decision on the detailed route would probably be made by the end of next year. The business case would be released publicly, she said.

The government was spending $25 million preparing stage 2, with $7 million allocated for the present round of tenders.

An industry briefing will be held on December 8.

The government plans to sign contracts for the building of the Woden line before the 2020 election, and Ms Fitzharris said it was doing everything it could to ensure continuity of work for the private sector, so there was no gap between construction of the Gungahlin line and work beginning on Woden.