One of the vans had been previously spotted in June in downtown Detroit, as shown on a map of Apple Map van sightings collected by Mac Rumors. The earliest listed was in 8/2014. The last update to the map was in 7/27/2015, so I will not bother submitting this sighting
The two new (as far as I know) items that the 12/10/2015 sighting adds
- The van had "Apple Maps" written on the side. Early sightings, before Apple announced the project publicly, did not have this.
- Apple has apparently finished focusing on downtown Detroit, and is now working on the suburban expressways. (The van changed from eastbound I-696 to westbound I-696.) They do not yet seem to be focused on residential areas in Detroit, unlike reported sightings in other metropolitan areas.