A 22-year-old Kuranda was so drunk when police pulled him over that their alcometers maxxed out at eight times the legal limit.

He then had to rushed to Mareeba Hospital by the Queensland Ambulance Service after experiencing a "medical emergency" due to his high intoxication level.

Police said medical studies have indicated an alcohol level of .400 per cent can be lethal and cause loss of consciousness and alcohol poisoning to the body.

Police from Cairns Road Policing Unit intercepted the motorist during patrols of the Kennedy Highway on Saturday morning.

Officers observed him driving erratically and intercepted his vehicle in relation to a traffic offence at about 7.45am on Saturday morning.

A police spokesperson said: "Whilst speaking with the male driver it allegedly became apparent he was effected by alcohol.

"A roadside breath test was performed and it returned an alleged positive result, one that was actually over the range of the Queensland Police Service roadside breath testing devices."

Acting Senior Sergeant Greg Rose said roadside breath testing devices have a maximum range of .400 per cent.

He said a driver to be found over that maximum reading is extremely disappointing and "somewhat horrifying" at the same time.

“The ability of a driver to control a vehicle at that sort of reading is severely comprised. It is almost a fatal crash waiting to happen,” Acting Senior Sergeant Rose said.

“The legal limit for an open drivers licence holder in Queensland is below .05 per cent, so for a driver to be at least eight times the legal limit on our roadside device is almost unbelievable.

"For someone to drive a vehicle when they have consumed that large an amount of alcohol shows a blatant disregard for the road safety of other road users."

A specimen of blood was taken from the driver and has been sent for analysis and pending the results he will appear in the Mareeba Magistrates Court in relation to the drink driving charge and a number of other traffic charges.