Sam's Transect of Toontown ranges from the T6 Urban Core to T1 Rural, and includes a Special District.
"D SPECIAL DISTRICT:
Imagine crossing under the Disneyland Railroad track. Once past the gates you will turn right and aim for the Roger Rabbit fountain. You have entered Toontown's industrial Special District. The fountain is out of place in an industrial area but this is Toontown after all. Then again, many modern industrial parks include some form of public art nowadays.
A Special District is an urbanized area devoted to a single activity. In Toontowns's Special District, you have typical industrial uses such as a trolley barn, a power plant, glassworks, fireworks factory, and whatever is going on inside Roger Rabbit's Cartoon Spin. The Insurance Company being in the zone makes sense considering how many Toons get hit with anvils and falling pianos."