Manal al-Sharif, 32, was held for nine days in May after driving in the eastern city of Khobar.
"We won't stop until the first Saudi license is issued to a woman," she told the BBC in her first interview since.
Earlier this week, prosecutors in the city of Jeddah announced they were going to prosecute a woman for driving.
The campaign to allow women to drive in Saudi Arabia has gained momentum in recent weeks.
On 17 June, dozens of women took to their cars across the country in open defiance of the ban on driving.
The campaign gained the support of prominent women around the world, including US Secretary of State Hilary Clinton.
Manal al-Sharif's imprisonment led to Amnesty International calling for her release.
She said she was surprised by the level of coverage and support she received. "I didn't know the whole world was moved."
More importantly, she said, had been the reaction from women in Saudi Arabia itself.
"Women tell me they are different since 21 May - the day I was arrested. It's a positive change, they believe now.  [Driving] is one of our smallest rights. If we fight, we can build women who trust themselves, have belief to get the bigger rights we are fighting for."
Some Saudi women say the authorities have slightly relaxed their attitudes to female drivers, merely cautioning women rather than making them sign a pledge not to do it again.
Earlier this week, however, prosecutors in Jeddah - on the Red Sea coast - announced they intended to pursue a case against a 35-year-old woman driver.
The woman, who has not been named, claims she had no alternative to driving as she needed to get to hospital and there was no man to take her there.
Zaki Safar from the Women2Drive campaign has spoken to her and said she had told the judge who set her trial date for September that he did not understand the background to her case.
Such setbacks appear not to be deterring many Saudi women from pursuing their campaign.
Manal al-Sharif, one of the organisers of Women2Drive, says they have been contacted by 1,023 women who want to drive - and by 192 women from across the country who are willing to teach them.
They are now looking to recruit volunteers.
"Women want to drive and they are taking actual steps towards that," said Ms Sharif.

Members of the Unite union working for Wood Group on eight Shell installations will vote on whether to strike.
The union said its members were "deeply worried" and felt they had no other option but to consider industrial action.
Wood Group said it was "extremely disappointed" at the news during the consultation process.
The platforms involved are Shearwater, Gannet, Nelson, Curlew, Brent Delta, Brent Alpha, Brent Bravo and Brent Charlie.
In February, Aberdeen-based Wood Group PSN announced it was cutting rates paid to about a third of its UK contractor workforce.

A wet outfield caused a delayed start and after a failed inspection at 11:30 BST, lunch was taken early.
Rain put paid to a planned inspection at 13:00 BST, and the umpires confirmed there would be no play after a further check two hours later.
Play will resume on Sunday with Lancashire 123-4, trailing by 57 runs.
A Saudi woman whose imprisonment for driving drew global attention to the issue says she is more determined than ever to continue her campaign.
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Hundreds of North Sea workers are to be balloted for industrial action in a dispute over pay cuts.
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There was frustration for Lancashire and Middlesex as rain prevented any action on day two, with play at Southport abandoned at 15:00 BST.