Interesting discussion.
The car in the dust problem would cause both cars brakes to be applied
immediately because the radar can see through dust at that range.
The car pulling into the on coming lane would be detected and a
calculation done taking into account all three cars speed and a
decision made to accelerate or brake.
The hacker problem is easily solved. Don't connect to the internet.

The big problem is EMI ! (Electromagnetic Interference.)
To build an older story for EMI, I was driving on the autobahn in
Germany some years ago and I saw these wires strung over the aurobahn
about every one or two metres. Puzzled about this I called up someone
on the radio I had in the car and asked about it.
It seems that on my left was Radio Free Europe beaming over the
road and the Czech border into Eastern Europe.

So the Megawatts had the effect of stalling the newer cars fitted with
electronic engine management systems.
The ADAC (=NRMA) had to position tow trucks at each end of that section.
This type of problem can be designed out but not always successfully
as those who have parked at Black Mountain in Canberra can testify.

Reading this debate, I am reminded of the search and rescue mounted when a driver got stranded in the Big Desert in western Victoria because he trusted the erroneous instructions from the car's GPS over the road signs on the highway saying 'To Mildura'.

SteeleRedux, I don't know how insurance companies assignment fault in an accident, fortunately never having had to find out.

As for the self-learning capabilities of vehicles, these would be very much less than children. I think we are a long way from treating a machine as an ethical, independently thinking person.

ps: There are regulations covering bullbars for vehicles, to take into account the injuries they may cause to pedestrians and passengers (bullbars protect the vehicle, not the occupants): https://www.vicroads.vic.gov.au/safety-and-road-rules/vehicle-safety/bullbars

EMI more:
In Europe cars, trucks etc are tested in a strong UHF field to
ensure that their systems including brakes systems continue to
operate as designed. Those tests probably eliminate 99% of EMI.
However two way radio systems in Europe had the effect that some
could not be used at knock off time as employees could not unlock
their cars.
This the same effect as Black mountain where cars cannot be unlocked
until the TV transmitters are turned off, hence the sign in the car park. Later systems use a different frequency band.

There are stories of cars in the US stalling or accelerating if a
nearby car transmitted.
Another story is the Sydney Harbour Bridge toll gates before etolls.
If you transmit as you reach the toll gates the gate opens without
having to put money in. Taxi drivers, couriers and the likes of us
soon woke up to it and it was a big joke on the DMR for a long time.
I used to annoy drivers who had radar detectors. Press the tx button
and it would turn their radar alarm on.

However all that was just to warn that all the programming skills in
the world may not be enough to make autonomous cars bullet proof.

A good point Cossomby.
If the current GPS systems can get it wrong so that some people get lost on the roads, the mind boggles at what could go wrong with Autonomous Cars.

I was also wondering how expensive these cars would be to buy for the average person, and how much the insurance might cost. I would imagine that both of these sums would prohibit the widespread use of such vehicles for quite some time yet.

TomW and the legs of van drivers !