In some Australian states, it’s illegal to start a car with the intent to put it in motion while you’re drunk. The rise of autonomous vehicles complicates things though. Sure, you’re three sheets to the wind and want to put the car in motion, but you're unlikely to hurt anyone by directing a car to taxi you through the Taco Bell drive-through a couple of times before you pass out in a cloud of tortilla dust.

An independent panel pulled together by the Australian government released a report this week trying to hash out the difficulties that governing bodies will face in rewriting laws for humans engaging self-driving systems. That panel, called the National Transport Commission (NTC), wants to develop a clear set of laws by 2020, and its paper (PDF) solicited feedback from key industry players as the panel moves forward.

Though it may seem obvious that a drunk person should be allowed to be taxied home by a fully autonomous car, the question is less clear if you have to determine just how autonomous an autonomous vehicle needs to be for a drunk person to operate it. The government should want drunk people to engage a high-level autonomous driving system if the alternative is driving themselves home, but if they’ll be penalized for being drunk while they’re “in control” of an autonomous vehicle, uptake of self-driving systems may be slow.

Instead, the NTC argues, drunk driving offenses should only apply to drunk people who are manually operating their vehicles but not to people who have merely started an autonomous car. The present rules "exist because a person who starts or sets in motion a conventional vehicle while under the influence clearly has an intention to drive,” the NTC writes.

The question gets more complicated, too, depending on who owns the autonomous vehicle. In ride-sharing situations where the car has been hired temporarily, it seems straightfoward that the passenger shouldn't be responsible if the self-driving car is involved in a crash. But if the rider is also the owner of the vehicle and claims they were in self-driving mode, how will law enforcement determine if that's true?

The questions are being raised in the US, too. At the Governors' Highway Safety Association meeting this week, US authorities discussed open container laws in autonomous vehicles. Currently, it's illegal to have an open alcohol container in a car while you're driving US roads. But should that apply in fully autonomous systems where no one is driving?

Who makes these rules and enforces them is its own debate in the US, too, with the Trump administration largely calling for a continuation of the Obama administration's "light regulatory touch" philosophy when it comes to automakers building self-driving cars. In Congress, the House passed a bill last month directing the National Highway Traffic Safety Administration (NHTSA) to adopt some guidelines for self-driving cars analogous to its regulation of manually driven cars.

Not just drunk driving

Australia's NTC paper was thorough in its description of laws that would have to change to accommodate fully autonomous vehicles. Drunk driving might be the most extreme example, but there are other driving infractions that become more complicated to parse when an autonomous system is behind the wheel.

These mostly involve actions that don’t clearly fall to the car or the passenger when an automated system is driving, including:

Paying parking fees where applicable. “In a dedicated automated vehicle with no occupant, there may be no party who can perform this task,” the NTC writes. “If the parking fee is not paid, the registered operator would receive an infringement notice, as currently occurs.”

“In a dedicated automated vehicle with no occupant, there may be no party who can perform this task,” the NTC writes. “If the parking fee is not paid, the registered operator would receive an infringement notice, as currently occurs.”

Using portable warning triangles. When a heavy-duty vehicle stops or when something has fallen off the truck, who is responsible for putting these warning triangles out?

When a heavy-duty vehicle stops or when something has fallen off the truck, who is responsible for putting these warning triangles out?

Making sure passengers under 16 years old are wearing seat belts. Currently this is the responsibility of the driver, but would a fully autonomous vehicle have to register the ages of its occupants to be in compliance?

Currently this is the responsibility of the driver, but would a fully autonomous vehicle have to register the ages of its occupants to be in compliance?

Fulfilling the duties of a driver involved in a crash. The NTC notes that in some US states, the obligations of the autonomous car have been fulfilled if the car remains at the site of an accident and if the owner or operator of the vehicle contacts law enforcement. But as more autonomous vehicles hit the road, that might become a cumbersome option, unless accident occurrence rates fall dramatically.

The NTC notes that in some US states, the obligations of the autonomous car have been fulfilled if the car remains at the site of an accident and if the owner or operator of the vehicle contacts law enforcement. But as more autonomous vehicles hit the road, that might become a cumbersome option, unless accident occurrence rates fall dramatically.

Securing insecure or overhanging loads. If something carried in the car pops out or becomes insecure, it’s the driver’s obligation to get out of the car to fix the situation. But how will an autonomous vehicle know that this dangerous situation has occurred, and what will it do to fix it?

If something carried in the car pops out or becomes insecure, it’s the driver’s obligation to get out of the car to fix the situation. But how will an autonomous vehicle know that this dangerous situation has occurred, and what will it do to fix it?

Taking direction from a police officer or authorized person. Human drivers can do this with ease, but fully autonomous vehicles will have to include some sort of programming to deal with these situations.

Legally, the NTC says, autonomous driving systems can’t be held accountable for not performing tasks they don't have the ability to perform. The challenge now is to divvy up these tasks among humans involved in the system, especially when fully autonomous vehicles hit the road and no driver whatsoever may be present.

Finally, another difficulty could arise from the mapping and decision limits of a self-driving car, making the car a road hazard in itself. If a car with “high automation” comes to the end of its domain or for any reason needs to make a safe stop without the passenger’s input, “The vehicle could remain there for a significant period—for example, waiting for an occupant of the vehicle to wake up.”