NZTA General manager of system design and delivery, Brett Gliddon, said the agency was determined to make the right choice for people who had waited years for the project to happen.
"So far, the business case process has been looking at a number of design options that could be possible; and we need to do more work before we know the right design to take forward,'' Gliddon said.
"We want to get it right the first time - including the right width - so more people can use it without restrictions; as well as the best materials to build the structure.''
The current proposal is for the construction of a 1km long 4m-wide path attached to the bottom of the bridge between Northcote Point and Westhaven.
Last August, it was announced that the Government would fully fund the $67 million SkyPath project.
It came as Transport Minister Phil Twyford and Greens co-leader James Shaw announced a $390m three-year cycling and walking package across New Zealand - much to the delight of the cycling community.
The SkyPath is a concept that was developed by the SkyPath Trust.
It is a charitable trust that has always been about creating a world-class walking and cycling facility on the Auckland Harbour Bridge.