VISITING Sydney last month, I noted that the light-rail project that has rent the CBD asunder and created traffic havoc along virtually its entire length still is nowhere near finished. It’s just possible that by the time the first light-rail vehicle runs from Circular Quay, we’ll all be in automated cars already and the public transport system will be redundant – especially one that can only go from point A to point B on one predetermined route with no detours possible.

Sydney is facing what one might describe as a “trolley problem”, trolley being an old-fashioned term for “tram” – like those commonly seen in Melbourne – which seems to be fast becoming an old-fashioned term for “light rail”. You might be familiar with the philosophical “trolley problem” thought experiment. There is no right or wrong answer to this, but how you respond says a lot about your view of the world, and your moral and ethical outlook, so here we go.

There’s a trolley hurtling down a track, quite out of control, with 10 passengers onboard. If the trolley keeps going, it’s going to run over the edge of a cliff and kill every passenger. As an aside I’ve never understood why anyone would build a trolley track that runs over a cliff, but that’s beside the point. And speaking of points, there’s a set that you can operate by pulling a lever that will send the trolley on to another track and to safety, but on that track there’s a child playing with toys, and the trolley will run them over and kill them. Do you pull the lever?

As I said, there’s no single answer to this problem and I don’t want to get sidetracked here by explaining why your response suggests you are a psychopath. The point is, everyone’s morals or ethics are different, which is why The Companion can be so entertaining because his essential world view swings wildly and unpredictably between an attitude that can be summed up by the word “meh” and the more extremely animated aspects of a combination of “OMG/WTF/you’ve got to be kidding me”. Something happens, flip a coin: he could go either way.

But anyway, the trolley problems – Sydney’s, and the thought experiment – have collided, though not literally, with the issue of automated vehicles as the designers of said vehicles grapple with the question of what “behaviour” they should build in. Say an automated car is chuntering down a road at a good clip when it suddenly and unexpectedly encounters a group of people on the road. If the vehicle ploughs into the people it will kill all of them. The only way to avoid the people is to steer off the road, but then it will hit a brick wall and kill the passenger. What should it do?

Unless you’re as erratic as The Companion, the way you answer this question should be close to how you responded to the original trolley problem. But the deliciousness of addressing this problem in real life is that you can get very different responses depending on how you frame the scenario.

What if the sole passenger in the automated vehicle is a pregnant woman on the way to hospital to deliver her baby? Are you more or less likely now to want to save her, and her unborn child? What if the passenger is a known paedophile out and about for no good – more or less likely to want to save him? What if the group of people are school children – more or less likely to want to save them? What if they’re cyclists? Less likely to want to save them, I bet. But you see what I mean. None of this stuff is simple, and it has to be thought about before we turn automated vehicles loose on our roads.

At least when a tram vehicle is skreeling along (a word which here I intend to mean that metal-on-metal sound tram wheels make on tram tracks), one of the elements of the trolley problem is removed: if there’s something in the way driver can’t decide whether to steer around it or not.

The more I think about this, though, the harder an issue it seems to be to solve. It might be such a tough one to crack that by the time philosophers and makers of automated vehicles solve their trolley problem, the NSW Government will have long solved its own.