Challenges for Self driving Semi

I touched on the potential for self driving semi in my recent Deep Dive on Union Pacific, and mentioned the lack of entrenched unions for trucking industry can be a boon for them to integrate automation compared to railroad industry which is heavily unionized.

The limit to this argument is trucker is the most common job in 29 states. As J Paul Getty said, “If you owe the bank $100, that's your problem. If you owe the bank $100 million, that's the bank's problem.” So, when your job is literally the most common job in 29 states in the US, you may not need to be unionized to push back against automation; the politicians may be amply incentivized to make life difficult for trucking automation by implementing ever stringent regulations. We will probably see this conversation about social implications much more once self driving semis start to hit escape velocity, but we aren’t there yet.

Chris Paxton wrote a good piece yesterday explaining the technical challenges of self driving semis and why companies such as Waymo have abandoned their self driving semis operations for now. A key excerpt from the piece:

Fully-loaded trucks are massive, with a legally-mandated maximum of 80,000 lbs. This makes everything a truck does notably less responsive.

If we want to discuss how serious a problem this is, we should look at stopping distance; i.e. how long it takes a semi truck to come to a complete stop because, say, there was an accident on the road ahead of it.

Stopping distance for a fully-loaded semi truck traveling at 65 mph is approximately 525 feet to about 600 feet. Even though most US highways have higher speed limits, trucking companies usually limit speed to 65 mph for safety and fuel efficiency reasons; it seems reasonable to expect that autonomous truckers would do the same. But note that this is under ideal conditions; stopping distances can as much as double on icy roads.

Now, a good long-ranged lidar could have 1000 feet of range. Aurora has a particularly good in-house lidar, with about 450 meters (~1500 feet) of range - much farther than many other options. But maximum range isn’t effective range, which is far more important. This is hard to estimate — it varies depending on conditions, on objects, and of course on the quality of the particular classifiers being used to interpret objects. This quantity is notably shorter than the maximum range on practically any sensor, by as much as about half; and we’ll also need to classify if this was a spurious detection (a plastic bag blowing onto the road, a cardboard box) or a serious issue.

And that’s setting aside other concerns: what if there’s a patch of black ice ahead on the road? The lidar can’t detect this at all, and it’s a huge issue for highway driving. There was a famously horrific 133-car pileup in Fort Worth, Texas in 2021, caused by black ice, which led to 65 injuries and six fatalities. If you watch video, you’ll see skilled semi truck drivers carefully bringing their vehicles to a halt through the event, minimizing damage to other drivers as much as possible.

All this is to say, we’re talking about a really important and very high-stakes perception problem. You cannot make any mistakes in this, or trucks will crash, and people will die.

ADI 3Q’25 Earnings

I will share some thoughts on ADI’s earnings behind the paywall.

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