Australia's transport authority suggests only "dedicated" automated vehicles -- built with no human controls -- should be exempt from current drunk-driving laws.

Australia's transport authority has cautioned against significant changes to drunk driving laws in the era of self-driving cars, arguing that only 'dedicated' automated vehicles -- without human controls -- should be exempt from current regulations.

All autonomous cars undergoing tests on public roads in the US are equipped with a steering wheel and other human controls. Even if the cars are completing an entire journey autonomously, a human still sits in the driver seat to turn on the vehicle and engage the self-driving systems.

An in-depth research paper (PDF) issued by the Australian National Transport Commission addresses the issue of intoxication. Laws in many states give police broad authority, assuming that anyone who starts a car intends to drive. A Level 4/5-capable car will eliminate the need to call a taxi for a safe ride home from the local watering hole, however a sober chauffeur would still be legally required to start the car and activate the automated journey.

"In a vehicle with high or full automation, the person's intention in starting or setting in motion the vehicle would most likely be to have the ADS safely drive them home," the NTC report says. "However, the NTC is of the view that the safety risk that exists if someone who is drunk decides to take over driving is too high. For this reason, a person who starts an automated vehicle and may take over driving should not be expempted from these offences."

The NTC argues in favor of exemptions or clarifications to avoid DUI charges for anyone riding in a dedicated automated vehicle, as "there is no possibility that a human could drive a dedicated automated vehicle so there is no safety risk associated with drink driving."

The risk assessments do not appear to consider switchable lockout modes that could disable manual override in a traditional vehicle that supports Level 4/5 operation. Such systems are presumably under development for other purposes. A lockout mode could allow a privately owned car to be deployed on a ride-sharing network without allowing client passengers to take over manual control. An owner could also drive to work manually and send the car back by itself to take the kids to school.

The drunk-driving question is only one among many potential issues involving an extensive legal framework that was written long before viable autonomous technology came into view.