In a semi, you don’t just drive the nose like a car. We are more concerned about the back of the trailer, as it does not directly follow the tractor. The longer the trailer, the larger the offset between the two. That’s why we make such wide turns. Especially right turns, as it is against the law to run over curbs.
A tractor trailer would require one unit on the cab and two on the trailer. Plus a way to connect them reliably - and also be compatible with every other trailer in the company.
Plus sensors for wheel spin in adverse conditions, automated connections for air and hydraulic lines, motors to raise and lower the landing gear on the trailer, sensors to ensure all of it was connected/disconnected properly, etc.
Imagine a computer deciding when it was ok to drive into on oncoming traffic in order to clear a trailer in a turn. Empty trailers have little or no traction when braking - emergency stop? Not.
The number of fatalities would make all the automation folks wish for the old days. And the costs of goods delivered would skyrocket. Because everything gets there by truck. Everything.
bottom line is maybe this can work for cars, i wouldn’t want it on trucks. imagine the cost of consumer goods going up to cover the extra liability. that cost gets passed onto consumers. nothing good will come of it. unemployment. more stupid unnecessary avoidable deaths. higher costs.