Naming streets would be so awesome, but I can also see how it would be more complicated than naming animals (or anything else made up of a grouped "asset collection"). Roads are made up of so many sub sections and AI naming can be more difficult.
In CiM2, streets were named, but they were only from one intersection to the next - and therefore more of a distraction. I prefer no name over every section of road getting a random name. The thing would be that all these little sections need to be "grouped" to form a road with one name. This grouping would have to take different road types and capacities and parallel one way roads into account as "one". And then intersections with multiple roads could confuse the entire matter.
Districts may work - but then it would become messy if you have to split up districts to name roads (and it would still leave smaller roads unnamed - or you end up with a massive amount of districts). An overlay, like laying down "strings" on a road may work - but it would still need to be intelligent enough to "split" in the center or be able to read to parallel roads as one.
In the end, I think, to provide a nice solution to this would involve some creative thinking and development that would add flavor but little gameplay aspects to the game. Maybe that is why we are not seeing such a feature at the moment; it got moved down the list for things that would add more gameplay features.