Улица translates as street, and дорога as road. The difference is that an yлица has buildings or houses lining it; a street cannot be isolated. Streets are in cities or populated areas. For example, if you are talking about someone's address (where they live) then you would call it a street, not a road.
Roads (dorogi) on the other hand, are more isolated. They are not lined by buildings or homes. They transport people from one town to the next. Roads are not found in cities, they are in villages or small towns. They are surrounded by more natural things than streets, such as forests or deserts.
