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Comment by JonoW | Hacker News Reader

The article mentions driverless trucks would drive slower, at 45mph, wouldn't this make a key difference in this scenario, eg a much shorter breaking distance. Also, a driverless vehicle has one option a manned vehicle doesn't - self destruction to save life, eg drive off the side of the road and crash (assuming it could determine that no one was there)

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That'd be a disaster on single-lane roads. Even with human trucks and their help (signalling if road is clear, driving on the shoulder when possible etc), it sucks to overtake them. If trucks were limited to 70km/h, there'd be much more need to overtake them. Which would either cause either traffic congestion or more drivers doing reckless things. Let alone that non-driverless trucks/buses/campers/etc would be stuck behind them forever.

I imagine they would start out only on multi-lane, limited-access highways. The small number of entry and exit points would make it much easier to program the truck. Such roads carry the bulk of long-distance truck traffic anyway.

Once you get away from highly populated and developed areas, there're lots of single-lane roads. Let alone that single-lane roads are used as backups when inevitable accident happens on multilane. Of course, there's not as much traffic in such areas as in those with multi-lane highways.

Well, the current tests with self-driving trucks are almost exclusively by european carmakers on German roads – where 2 to 3 lanes are common about everywhere, and trucks are limited to 80km/h or 100km/h anyway.

>. Also, a driverless vehicle has one option a manned vehicle doesn't - self destruction to save life,

Don't they?

https://en.wikipedia.org/wiki/30,000_Pounds_of_Bananas#The_i...

It's difficult enough for driverless cars to know where the lines on the road are. I don't think we can expect in the near future to be able to not only detect pedestrians, but to have an idea what series of events may happen during an avoidance maneuver. There's a lot of things to go wrong.

However, stopping distance in real-world scenarios is wayyyy farther than in practice runs, because even a second faster braking by the driver can save a hundred feet. So robotic braking (that we have today in passenger cars) could improve the distance a lot. But...

Trucks are still 10-20x heavier than passenger cars, and there are practical upper bounds to the size of their brakes and the g's they can pull. If a passenger car normally stops in 388 feet at 65mph (not uncommon) and it would stop at 196 feet at 45mph, a truck at 45mph would stop in 265 feet. So yes, the truck could in theory stop faster than the passenger car.

But passenger cars don't just slam on their brakes in front of trucks (often). They also just drift right the heck into the truck. Perhaps mechanisms could be developed to safely merge away, and they'll probably be developed in passenger cars first. But there's no denying that a dedicated roadway would not only save repair costs for passenger-vehicle-only roads, it would remove the risk of colliding with passenger vehicles no matter whose fault it was.

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