It comes shortly after the Government warned in a £750,000 campaign that sleepy drivers could be responsible for 300 deaths on Britain's roads every year.
BMW says the system it is testing gathers information from how often the driver blinks. If it recognises that they are getting tired or are tired it gives feedback via a visual display.
'An initial result of the research project is a system that informs the driver in which of the four alertness or tiredness stages they are in,' BMW said.
BMW said it differentiates between four stages of alertness and tiredness: 1 – awake, 2 – less alert, 3 – tired stage, 4 – drowsy.
'Drivers who are in the drowsy state are in danger of falling into a microsleep or falling asleep completely,' the firm added. 'The system being tested gives drivers the information from the alertness assistant via a visual display.'
BMW said it was possible to integrate an additional acoustic warning to alert the driver to their drowsy state.
However, it added: 'Here the typical approach of the BMW Group is not to wait with the warning until the driver is already drowsy, but to warn him before this, when the alertness is only slightly diminished.'