Bumper to bumper is a myth told to people who desperately want automation to solve congestion but we already know it won't.

This isn't a problem limited by automated systems. This is a problem limited by the physics of all the moving parts including tyres and breaks.

Paris metro line 14 is full automated and breaks in perfect timing every time but it needs 60 seconds between trains anyway. It has a reaction time of zero seconds but still needs 60 seconds between trains because of physics. For cars this time might be less than 60 seconds because they are smaller but added together it adds up to very large spaces between vehicles.

That will not change at any point in our lives. An automated car would actually make congestion worse because it makes additional journeys while empty every time the destination from journey1 doesnt line up exactly with the start of journey2. Realistically most people in sprawling locations will buy their own so it probably wont solve parking either.

The solutions to these problems involve re-allocating space away from roads and parking. That's where the really exciting changes are happening.