Hacker Newsnew | past | comments | ask | show | jobs | submitlogin

Yes. Truckers have to deal with a sort of standard "road safety dilemma" all the time, which can be boiled down to this:

A trucker is driving a 40 ton truck at 65mph. A passenger car with a family of four cuts in front of it, and the distance is closing fast.

A passenger car takes roughly 315 feet to come to a complete stop. A fully loaded truck takes 525 feet. The trucker now has to make a decision.

A) Do I slam on the brakes and keep going straight, and completely obliterate the car in front of me and the family inside it?

B) Do I cut off to the side, running over the rail, flipping the truck, killing myself, and possibly any other vehicles or pedestrians around, behind, or coming in the opposite direction of me?

The robot trucker could of course decide on B), but there are unknown variables about the extent of the resulting damage. This risk increases with merging between lanes or on/off ramps both by passenger vehicles, the truck itself, and motorcycles.

A dedicated lane would make this fantastically safer, but who will pay for it?



>A passenger car takes roughly 315 feet to come to a complete stop. A fully loaded truck takes 525 feet.

How does this change if truck design and "per-axel" fee incentives were rationalized[1][2] to instead maximize the number of axles? Doubling the number of axles reduces road damage by 94%. Currently semi trucks account for 6% of vehicle miles driven[3] and 99% of all traffic damage to roads.

But would this measure also improve braking distance and safety?

[1] http://www.nytimes.com/1989/07/26/business/economic-scene-be... (erroneously states that damage scales as the cube of axle weight; it scales as the fourth power or even the sixth(!) power on weak roads)

[2] https://truecostblog.com/2009/06/02/the-hidden-trucking-indu...

[3] http://www.princeton.edu/~alaink/Orf467F13/FreightFacts&Figu...


Braking distance is a factor of speed, weight, brakes, tires and road surface. A 40 ton truck can only stop so fast with rubber tires on typical brakes on a typical highway road surface.

Race cars are designed to stop faster than passenger cars. Their brakes are huge, they're designed with exotic components to transfer heat to air faster, designed to take higher heat for longer, the cars are designed to flow air over the brakes, and they cost much more and don't last as long, and have advanced computerized systems to optimize brake utilization. They also have pretty big tires (usually for power transfer, not braking). Their tires are also grippier on a given surface at a higher tire temperature, so they cost more and don't last as long, and work best on dry flat surfaces. They strip all the weight out of the car to decrease the amount of force working against the tires and brakes. Even the suspension and shell is designed to increase tire, and thus brake, traction. They stop really goddamn fast - 93 feet for a Ferrari F430 Scuderia, from 60mph.

Trucks are designed to carry 40 tons up and down hills, survive tire blow-outs, brake system failures, and more miles than 1000 F430s will ever see, on all kinds of road surfaces and temperatures. It is possible to improve the brake time, but it would probably cost so much you might as well ship your produce in a Ferrari. Halve the weight they carry to reduce braking distance and now we have to have twice the trucks to carry the same loads, but you still have a vehicle 10x heavier than other vehicles with dynamics that simply can't move around like the lighter ones. More accidents would be guaranteed.


> Race cars are designed to stop faster than passenger cars. Their brakes are huge, they're designed with exotic components to transfer heat to air faster, designed to take higher heat for longer, the cars are designed to flow air over the brakes, and they cost much more and don't last as long, and have advanced computerized systems to optimize brake utilization.

A lot of that isn't to brake faster but to keep the brakes from overheating from constant high use during a race that can last a couple hours or more. For normal emergency use you can drop a lot of that because they only need to be used extremely hard rarely and they'll have time to cool.


In other words, look at aircraft, not at racecars. What you have described is practically the only mode of operation for wheelbrakes there ("brakes catch fire during emergency braking? No biggie, just keep an eye on them while they cool.").


Brake heating is not a real issue with emergency braking, only with frequent braking which race cars do. That's why "upgrading" to "big brake" systems on passenger cars is usually a waste of money and reduces performance: unless you're driving on a track where you have to brake a lot, and the cumulative braking keeps the brakes hot, you're not helping. Even worse, the brake pad compounds used for race cars are different, and are designed to maintain performance even when very hot, whereas passenger car brakes have to have great performance when cold.

The bottom line is: a single panic stop on the highway isn't limited by your brakes on a passenger car, it's limited by your tires. The more friction your tires have with the road, the faster you'll slow down.

So yes, if you want a 40 ton truck to stop faster, it's completely doable: just increase the amount of rubber in contact with the road. Adding more wheels will do that quickly. However, more tires means more rolling friction which means less fuel economy and fuel economy is critically important to long-haul trucking. Also, adding more axles causes maneuverability problems in the city. Notice that on standard trailers, the rear axle set can be moved forward and back. They set them in the rearward position for long hauls, and in the forward position for shorter hauls.


If there's no driver in the equation (no monthly salary to pay), I guess the the incentive will shift towards having more, smaller trucks.


Not necessarily. More, smaller trucks will mean your transport costs will go up because you get less economy of scale. Eliminating the driver helps mitigate that of course, but going to smaller trucks then eliminates the savings you got by eliminating the driver. Having more, smaller trucks would be more versatile however, if you don't need to transport full truckloads of cargo between certain points.

Also, drivers as I understand it aren't paid monthly salaries, they're paid by the mile.


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)


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.


There's a real possibility that once driverless trucks become widespread, human behavior will change as well. A very aggressive driver may take advantage of the fact that an automated truck will brake for them, and start routinely cutting off trucks, whereas today they'd be a little more respectful. Even pedestrians could start crossing a highway where they shouldn't and know they could get away with it.


The next step in this progression is that trucks report cars being purposefully a danger to them, with video evidence.


A robot trucker will never do (B). The car put itself there and can presumably get itself out again. More importantly, swerving will lead your truck to jackknife and roll in unpredictable ways and cause who knows how much extra damage.

As I've said before about smaller autonomous vehicles, they'll be programmed to always choose the option which is most defensible in court. I will be amazed if we ever see an autonomous vehicle on public roads which does something more complicated than "come to a complete halt as fast as possible while steering for the clearest area of asphalt."


There are situations where the safest course of action is to accelerate, or maintain speed, while maneuvering. I'm sure we'll get there if the trend of automating individual driving tactics continues.


"And then, your honour, the truck accelerated and struck a busload of orphans!"

"Case closed."

(I agree but humans are dumb and companies have to cover their asses.)


Robot chooses A) and also immediately uploads footage to the DA Idiot that caused roadwreck is sued for that (I'm pretty sure there are specific laws against causing massive damage. In my country at least, there are.)

Soon, people learn that they are responsible for acting, well, responsibly.


or, apply full brakes, apply full audible warning and swerve at the last possible moment, while calling the emergency services to put them on alert.

But how common is your scenario ?

I consider this a more critical failure :

The Federal Motor Carrier Safety Administration suspects that as many as 28% of commercial truck drivers have sleep apnea.

The Sleep Medicine Division surmised that nearly a 250,000, persons fall asleep while driving each day of the year.

Nearly half of semi-truck drivers have admitted to actually ‘drifting off’ while driving a long-haul route.

https://www.hg.org/article.asp?id=29866


> But how common is your scenario ?

Anecdotally, the 3 truckers i've known have complained about it. I now drive very carefully around trucks.

Swerving at the last minute is a non-option because it means turning sharply, which jackknifes the truck. Turning while braking is worse because turning while either braking or accelerating compromises steering. You can try to brake until the last moment and then take off the brakes and try to turn, but again possible jackknife, the wheels could have locked up to the brakes, and now that you're traveling slower you will actually turn slower, so it's harder to cut the wheel and go around. All of this within a few seconds.

You have to either try to slow down and blow the horn, or get out of the way and blow the horn. Some people are lucky and either swerve away from the truck at the last moment, or their car only gets marginally crunched.

One hacker friend of mine's car actually got thrown nearly into the opposite lane of traffic on the highway with the same scenario. Recovery took a while. I think he's still got pain and limited mobility.


Of course, being automated allows for much more advanced braking schemes.


I don't doubt the cut-ins but I mean, how common is the disaster part?

Not as often as truckers having incidents through tiredness etc. I'd warrant.

> You can try to brake ....

We're talking about "The computer ...."


I haven't seen a jackknifed lorry in a very long time, I thought that had been solved with anti-lock brakes.


For this reason alone I would trust autonomic trucks much more than human driven counterpart. I must admit, I've drifted away few times as well while driving passenger car over long, boring highways..


Given that an automated truck will follow a certain safety framework, it's interesting to contemplate if there might be automated truck pirates.

Jam mobile connectivity, run the truck off the road by herding it with other vehicles, then break in and run-away with the goods or the entire trailer for that matter.


You can also do that with a human in the truck. I'm not convinced that it will happen more often with automated trucks.


Most humans will keep driving, even without mobile connectivity. Also, destroying electronic witnesses isn't (yet) murder.


This is one of many reasons we will still need humans present, if only in a guard capacity.


Meanwhile, cargo ship companies are looking toward automation and remote control to get humans off the water. Pirates aren't scared of humans being on board, and in some cases they prefer it, because a human crew is worth more ransom.


Your house sits empty all day and nobody robs it. Video cameras work pretty well for this if it becomes a problem. Great to live in a country with rule of law.


Trucks routinely carry cargo worth many thousand times the value of the average household's possessions.


If a cargo was valuable enough, a driver's life would only be a collateral damage. Furthermore, all (non military or security) personnel training programs I've encountered specifically highlights, that in a case of armed robbery, do not resist, obey and do not escalate conflict in any other manner while trying to call help unnoticed.


Granted, but a human guard nevertheless presents a problem for robbers.

Do you take the guard hostage? Do you kill them? Will they themselves be armed? Will they put up a fight, training or no training? If you try aggressively to bring their vehicle to a halt, will they concede immediately (as an autonomous vehicle likely would), or will they try ramming your vehicle?

A human guard is an unknown quantity, and any crimes you commit against their person are in a different league to the theft of the cargo.


this can be deferred to local security companies with nation-wide contracts.


I think the worry also is that at some point, hundred years into the future someone somewhere might write the code where the truck will go "I'm carrying 1 million dollars worth of cargo which would be destroyed if I drive into the ditch, but the cost of litigation for smashing into this small car that clearly broke the law and will be at fault in this situation is smaller - continue program;".


Don't forget C) attempt B and jacknife your truck across several lanes killing the occupants of the car that runs into the side of your trailer...


'Truckers have to deal with a sort of standard "road safety dilemma" all the time...'

I think you mean that truckers FEEL like they deal with that dilemma all the time. If they ACTUALLY dealt with an A or B dilemma, they would routinely end up in situation A or B: running over a passenger car or flipping the truck. It happens SOMETIMES, but infrequently.

In reality the situations where other drivers do something stupid are probably much better handled by the self-driving truck, which doesn't panic, doesn't feel a fight-or-flight response, doesn't overstate the gravity of the situation... doesn't do anything except assess what to do next without emotion.


I am convinced. Ban trucks.




Consider applying for YC's Fall 2026 batch! Applications are open till July 27.

Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact

Search: