Hi Minerva,
In case you are interested, the updated Complete Streets Rule has more information about it here: Complete Street Rule Update
The answer I think is yes, you can create streets in CityEngine and export them as a scene layer package directly from CityEngine. You should either also create your buildings in CityEngine, or at least import their footprints/parcels so that you can have a good placement of streets relative to other assets/buildings.
Others might have better advice.
David
David Wasserman, AICP