Transport Agency highway manager Ross I'Anson said physical repairs, including installation of new rockfall netting and reinstatement of a damaged retaining wall, were on track to be completed by the end of this week.
However, further geological assessments of the slip sites were needed to assess the potential risk of further slips or rockfalls before the road could be safely opened.
Tararua District Mayor Tracey Collis said safety in the gorge was paramount.
"The significance of the slips is always a concern and a number of our residents have known people whose vehicles have been hit with falling rocks," she said.
"I know this wasn't the news people were expecting and it won't help the pain people are feeling and I want the NZTA to keep to this three-week date to give businesses a good opportunity to plan forward."
Mrs Collis said she had travelled over the Saddle Rd and expressed her concern about the state of some parts of it. Once the Gorge was open she wanted work to be completed as soon as possible.
Mr I'Anson said NZTA was working with its contractors and independent geotechnical engineers to complete the assessments as soon as possible.
"But these evaluations must be thorough to ensure the road is safe when it is reopened," he said.
"While the slips have been cleared and the road has been repaired at both sites, the slips have altered the rock faces above the road and we need to thoroughly assess any
additional risks the newly exposed rock might pose for road users.
"The recent slips have resulted in new cracking in the rock faces on either side of the slips and we need to identify if there is a risk of additional rock falling on to the road and, most importantly, what additional work may be required to provide further protection for road users. The geology of the gorge is complex and these assessments must be very thorough to address that complexity."
Mr I'Anson said it would not be known what, if any, additional work might be required until the geological assessments were completed, a process expected to take up to three weeks.
"We understand how frustrating the current situation in the gorge is and we know the significant impact it is having for road users, businesses and residents but the safety of road users is paramount."
He said that in parallel with the geological assessments of the gorge slip sites, NZTA would be progressing with the detailed business case process to look at all of the options available to provide a long-term, resilient and safe connection through the Ruahine/Tararua ranges.
Mrs Collis said she and other regional mayors would be pushing for a long-term solution.
"We will be making sure the Gorge funding is a priority in regional and national transport plans."
New Zealand First deputy leader Ron Mark, in Dannevirke last Wednesday for a breakfast meeting, said he didn't understand why it was taking so long to find a solution to the continuing problems with the Gorge.
"The Gorge is the lifeblood connection for Tararua and it's strategic for the nation," he said.
"After all the work which has been done and all the money poured into the Gorge, we need solutions."
Mr Mark said he believed a cut-and-cover option might be the best but he'd also like to see a feasibility study on a tunnel.
"Connectivity is important for regional development and I look around at all the money being flicked into Auckland, but the Government needs to be pushed like hell to put money into a final solution for the Gorge."
