Doctors have voted in favour of further research into the dangers of driving with dementia being carried out in response to fears that many sufferers are not safe on the roads.
Dr Peter Holden told the British Medical Association's (BMA) annual representatives meeting in Liverpool that current DVLA guidelines are "too general to be helpful".
"They concentrate on individual conditions as they impact on the ability to hold a driving licence, rather than on the person as a whole's fitness to drive," he told delegates.
"The guidance on dementia runs to five lines. The act of safe driving requires integration of a complex set of often fast changing sensory inputs coupled with swift reflexes and a high degree of judgment - all factors affected by dementia."
His two motions, which called for the BMA's Board of Science to produce a report on the matter as well as amend the criteria for obtaining a blue badge to make them available for people with dementia, were contested by council member Dr Stephen Watkins, who said it was "far too simplistic".
Dr Watkins said a "comprehensive policy on transport for older people" was needed to address the reasons why so many elderly people rely on driving to get around, particularly in areas where public transport is limited.
Psychiatrist Dr Deirdre Shields said "the ability and facility to drive is cherished".
"It is a fundamental part of modern life," she added. "When a person has advanced dementia it is clear they can't drive. However, people are already seeking diagnosis when their impairments are still mild. Further research is badly needed."
The motion for the Board of Science to carry out a report was passed with a "very, very large majority", representative's body chair Dr Ian Wilson said.
The second motion relating to dementia patients being eligible for blue badges was also "convincingly passed", he added.
Speaking ahead of the vote yesterday, Dr Holden said his "great concern" was that one day someone medically unfit to drive will "put a car into a line of children".
Would you let a dementia-sufferer "out with a shotgun?" he asked.
He said current rules mean that anyone diagnosed with dementia - or other significant medical conditions - should inform the DVLA so they can be assessed, but many do not. Others may not have had the problem diagnosed, or may forget to inform the authorities if their memory is affected.
Dr Holden, a GP in Matlock, Derbyshire, said he did not want to see a "nanny state".
"If we are going to have an increasingly mobile dementia population, I do think that the rules need to link up," he added.
Although it was down to the DVLA to decide if motorists were safe on the roads, he said doctors can also offer guidance. "I have a duty to the patient so they don't put themselves in a position where they, God forbid, mow down a row of kids," he said. "If I didn't tell them that, who else is going to?"
Head of policy at Alzheimer's Society, George McNamara, said: "A dementia diagnosis is not in itself a reason to stop driving. The critical issue, both legally and practically, is whether an individual is able to drive safely.
"This decision requires individual judgments which can be clinically difficult and need sensitive handling. We are working with the DVLA and others to provide greater clarity on how this assessment should best be done."
Andrew White, medical adviser at the DVLA, said: "All drivers must ensure that they are medically fit to drive and to notify DVLA of the onset or worsening of a medical condition affecting this. Age alone is not a reliable indicator of a person's fitness to drive."