The photo below is an example of the current required driveway width in residential single family subdivisions.  According to Title 21: Land Use Planning, page 7-133, the “total width of driveway entrances to a residential lot from a street shall not exceed 40 percent of the frontage of the lot or 33 percent of the frontage if the platting authority or traffic engineer finds that conditions warrant it”.  
The intent of these limitations is to provide adequate space for snow storage within the right of way, to have space for on-street parking where appropriate, and to discourage the majority of the front area of a lot from being paved and/or used for vehicle parking.”