"Her phone polled in Otara in Counties Manukau about 2am but the vehicle had gone when Police arrived and the next message we received was that she was now heading for the Coromandel.
"While this was going on Police were scanning any reports of unusual or concerning driving as we attempted to find the Toyota and prevent a potential tragedy."
Mr Litton said about 3.45am the woman's phone polled in Te Puna near Tauranga before her car was found up a driveway at her former address in Mt Maunganui about 4.55am.
"The woman's cousin found her, asleep, slumped over the wheel. When woken she had absolutely no recollection of the events overnight and we have sought an urgent order forbidding her to drive and to seek medical advice on her suitability to remain holding her drivers licence.
"While her being found safe and well is a relief for everyone involved the potential for tragedy was huge and we're urging people suffering medical conditions to be open and honest with their doctors and seek advice on if the medication they are prescribed affects their ability to drive or not."
Mr Litton also urged people on such medications to be frank with loved ones and friends so steps can be taken to ensure they don't put themselves or those dearest to them at risk.
"Safer journeys being everyone's responsibility isn't just a slogan it's an obligation we all take when getting behind the wheel. Last night's events could have so easily ended in tragedy which is something I am sure, we all want to avoid."