I have seen a number of articles about autonomous vehicles that pose dilemmas that drivers rarely or never need to face and pose the question of how autonomous vehicles should handle that situation. I am left wondering why these people are posing artificial situations that are only hypothetical and may never occur rather than looking for instances in the past where a situation has actually occurred that such vehicles would therefore need to be able to handle. One situation I can remember from many years ago makes a far better example of the type of dilemma that an autonomous vehicle would need to handle than any of these hypotheticals I have seen.On the main expressway north of Sydney there are many steep sections. Trucks descending these sections need to spend a lot of time braking and so brake failures occur frequently enough that emergency ramps have been installed at several places to deal with runaway trucks. These emergency ramps are near the bottom of these steep sections and these bring trucks to an eventual stop by providing an initial steep climb that slows the runaway truck and which I assume eventually provides a level spot where the truck is expected to stop (I haven’t been up any of these ramps to look). With the terrain in the area most of these ramps are cut into the side of cliffs where there is a vertical rock wall on one side and a long drop on the other.
On one occasion a car transporter carrying half a dozen or so new cars had its brakes fail and had to use one of the ramps. Now as it happens a family that had no idea what the ramps were for had decided to have a picnic part way up the ramp where they were not visible to any runaway vehicle faced with the choice of using the ramp to try to stop or continuing down the expressway and probably colliding with other vehicles causing a major accident. Now I know what the truck driver decided to do in this situation as I actually saw what was left of the truck and the car that had been on the cab roof but I don’t agree that an autonomous vehicle should necessarily be programmed to take the same action. The several people picnicking on the ramp were somewhere they were not supposed to be while the truck was using the ramp for its intended purpose. While the truck driver decided to kill himself in order to avoid helping the picnickers to commit suicide I don’t believe that an autonomous truck should make that decision on behalf of the driver in this particular circumstance and I also don’t believe that it should give the driver an opportunity to make the decision. In this particular situation I would expect an autonomous vehicle (with failed brakes) to use the safety ramp for its intended purpose and to disregard anyone illegally in the way (to do otherwise would make it far to easy to sabotage the reason for the ramps in the first place).