Acting regional director Bruce Richards said the bridge project had been investigated and there was a proposal to do preliminary design work so that the project was ready for a design and build contract.
"This will enable a rapid response in the event of future traffic growth."
The one-lane bridge, which is controlled by traffic lights and prone to peak-time traffic queues, would be superseded by a new two-lane structure.
The existing 1926 bridge would remain, because it is built on top of the Lake Wakatipu outlet control structure, and the new bridge would be built over the Kawarau River downstream from it.
Initially, NZTA had planned a full design contingency package to "put it in the draw", but it will now call for contract tenders "asap" on a basic, preliminary design, Mr Richards said.
The four- and five-star Hilton hotels could be open by late March, but when asked about the earliest possible construction date, Mr Richards said, "I won't guess as to when the bridge will be built".
He said the project was prioritised - alongside all other projects in the region - through the National Land Transport Programme, which is reviewed every three years; the next time in 2012-13.
"The NZTA is aware of the potential for growth, including residential development on Kelvin Peninsula, Jacks Point and Henley Downs, as well as commercial developments including the Hilton hotels and Remarkables skifield.
The NZTA also recognises SH6 south of Frankton as a significant tourist route. For these reasons, the project is in a good state of readiness to respond to potential growth," Mr Richards said.
Marlene Poynder, the newly-appointed general manager of the twin Hilton managed hotels at the $1 billion development, said although the bridge-widening was not a pressing concern for the group, she hoped it would eventually be addressed.
"Do we think people won't stay in Kawarau Village because there's only a one-lane bridge? No," Ms Poynder said.
"Understandably though, we will have more traffic - we would put it high on our priority list," she said.
Although he said the proposed bridge was "competing with other projects around the country" for funding, Queenstown Lakes District Council transport manager Denis Mander said the council had been lobbying NZTA for "at least six years".
"The issues for us have been increasing congestion around the intersection and emergency access to Kelvin Heights," Mr Mander said.
