I'm guessing that will be part of Level 5 or at least we will be very close to level 5(full) autonomy once complex situations like 4-way stops with lots of pedestrians have been mastered.
No.... They would work perfect on a highway WAY before we have cities figured out. If autonomous cars and trucks work on highways, then millions of jobs go poof.
Highway autonomy will be a nice feature but you still need a competent human driver to be present for end to end transportation. So I still need to order a car with a driver to get to the airport.
I assume that you're referring to trucking. It's possible that trucking companies will set up depots right off the highway and will reduce drivers as a result. But a lot of long distance container transport is already done by trains so it's not immediately obvious that eliminating drivers for only the highway portion of trucking is necessarily a big enough win to make it happen. (Especially if autonomous driving systems allow for the driver to sleep in his cab while underway.)
They won't be fully autonomous until we reach level 5, that is what level 5 is by definition. Whether or not a car that isn't fully autonomous but can handle a variety of common situations is completely useless to someone is an individual assessment. I personally look forward to the extra safety.