A question to challenge assumptions.
Is there substantive differences between single-family residential and two-family residential?
The general points usually are traffic, scale, unit density, building bulk, rental/owner occupied, etc.
I, personally, see little difference, on average, bewteen single-family residential and two-family residential. You could have a single-family house with 6 occupants all driving and have a "parking lot", whereas a two-family could also have 6 occupants each driving.
What are your thoughts?