Transport Secretary Mairi McAllan failed to confirm if an expected update on dualling the A9 will include dates for the remaining sections waiting to be upgraded.
Concern was also raised about the A96 dualling timetable, after questions over the impact of a climate report.
The major road projects have been hit by delays with pressure mounting on the Scottish Government to take action to speed up progress.
Dualling the A9 between Perth and Inverness will no longer be completed by 2025 with a revised target timescale yet to be published.
In Holyrood on Tuesday, Ms McAllan told a committee of MSPs it is her “intention” to outline “next steps” for the A9 by autumn this year.
But she failed to confirm if this will include dates for delivering the remaining nine out of 11 sections of the road that still need to be dualled.
Work on the A96 between Aberdeen and Inverness is yet to begin despite a 2013 target completion date.
Ms McAllan admitted the outcome a climate review “could have a bearing” on whether the road is fully dualled.
She said more details will be given in summer.
‘Still decisions to be made’
The SNP first promised to dual the A9 in 2007 but the government admitted earlier this year this was “simply no longer achievable” because of economic pressure.
Campaigners have been inundating the Scottish Government with demands to upgrade the road after more than a dozen tragedies on the route last year.
Asked if the A9 dualling programme will be provided in autumn, the SNP minister said: “I’m not going to pre-empt what I will tell parliament because there’s still decisions to made.
“There’s still a great deal of work ongoing. I will set out with a backstop of autumn this year, the next steps of the dualling programme.”
The SNP promised over a decade ago it would dual the A96 between Aberdeen and Inverness.
But this was thrown into doubt when the Greens were brought into government last year, with a climate review ordered.
Ms McAllan, appearing before the net-zero, energy and transport committee, said the government still plans to take the full A96 dualling project forward but is undertaking the review.
She said: “We are taking forward the work. Part of that was a climate compatibility test.
“We have got outcomes of work we have done that are due to be available this summer and then it will go for final consultation this summer.”
Liam Kerr, Scottish Conservative transport spokesman, criticised the SNP-Green government over the uncertainty around the A96 project.
He said: “Anyone in the north-east listening in, hoping for some clarity on the SNP’s plans, will have been left disappointed.”
He claimed the prospect of a “veto” by Green leader Patrick Harvie is “very real”, adding: “Mairi McAllan seems just as unable as her predecessors to stop it.”