In addition to the information delts has provided relative to Herriman Towne Center, the link below is the site plan I found from Sorenson's website:
http://www.thesorensongroup.com/img/...-Plan-half.jpg
Herriman TC's site plan resembles a neo-traditional development. Basically a cross bread between suburbia and urban characteristics in the sense that the streets connect, but have a suburban feel at ground level (i.e. curving streets, parking lots). IMO it is suburbia's excuse of an urban development, but it works well relative to traffic flow and some density. Another characteristic of these types of developments is that commercial and retail areas are segregated from the residential areas. The commercial and retail areas are usually around the peripheral; closer to major arteries that surround the planned development - could be a reason why traffic is a minimal issue.
The neo-traditional concept started in the early 90's and was widely accepted throughout the US through other various projects. Although I am not very thrilled with these types of development, the street network of neo-tradtional developments keep the traffic moving with minimal issues and structures, for the most part, have minimal amounts of setback from the streets.
It always good to read/ hear about local governments having confidence with upcoming developments despite the current economic situation. Now I (and I am sure others) hope to see this project commence soon.