I have had exactly this on a 70mph 2 lane road in Britain known as a dual-carriageway. I will phrase this carefully because we drive on the left, so the overtaking lane is on the right.
I was following a 'Luton van' (Which is like a small truck body on a normal 3.5tonne class long wheel base van chassis, you might call it a small box truck in the US). Incidentally Luton Vans are not allowed to go 70mph on a dual carriageway, they are limited to 60. I couldn't see past at all due to his wide body, so I was following at a safe distance and matching his speed at 70mph. Suddenly he swerved into the overtaking lane and I was met by a queue of stationary traffic! I knew this road well and stationary traffic would not normally be backed up this far. I braked very hard and felt the ABS rattle. I had just enough time to realise that there was a narrow gravel shoulder on this section I could turn into if needed, but the car grabbed just in time to not need that option. It was one of the scariest things to happen to me on a road. If I had been tailgating the truck I would not have had nearly enough time to stop and it would have caused a really nasty accident as I would have hit a stationary car into a line of stationary cars. I don't see how lidar, radar or cameras could have helped much, except to have reduced the reaction time slightly perhaps? It probably would not have been able to judge that the shoulder was a good alternative option.
Emergency Brake Assist would help if the van was equipped with it.
Swerving at the last moment and without warning would not be possible because EBA would activate brakes earlier and you would be able to see van's stop lights.
I was following a 'Luton van' (Which is like a small truck body on a normal 3.5tonne class long wheel base van chassis, you might call it a small box truck in the US). Incidentally Luton Vans are not allowed to go 70mph on a dual carriageway, they are limited to 60. I couldn't see past at all due to his wide body, so I was following at a safe distance and matching his speed at 70mph. Suddenly he swerved into the overtaking lane and I was met by a queue of stationary traffic! I knew this road well and stationary traffic would not normally be backed up this far. I braked very hard and felt the ABS rattle. I had just enough time to realise that there was a narrow gravel shoulder on this section I could turn into if needed, but the car grabbed just in time to not need that option. It was one of the scariest things to happen to me on a road. If I had been tailgating the truck I would not have had nearly enough time to stop and it would have caused a really nasty accident as I would have hit a stationary car into a line of stationary cars. I don't see how lidar, radar or cameras could have helped much, except to have reduced the reaction time slightly perhaps? It probably would not have been able to judge that the shoulder was a good alternative option.