One option to reduce convoy risk is have cars attach to one another such that no single car can cause a failure in the overall system (similar to trains).

We shouldn't think of automated cars as independent as we do. They are in fact simply compartments.

With that in mind, imagine cars attaching to each other to form trains and break apart as they begin to reach the desired destination.

This also has impacts on fuel efficiency since drag can be reduced across the entire system.

(Cars don't have to be the same model, they just need a formalized attachment system on the front / rear).