MIT (and in particular the City Form Research Group) has recently released an application called Urban Network Analysis (UNA) which measures how the layout of a city impacts the life of the people in it. This is done by taking into consideration many parameters such as for example the volume of traffic and the number of a variety of services and resources available to the populace. Buildings themselves are also very important to the calculations taking place.
More importantly, the application is completely free and available for ArcGIS as an open-source plug-in. It is definitely recommended that urban planners/modellers (seeing that applications like CityEngine are now integrated in its pipeline this could be of significant interest to 3D virtual city creators too) check this out here.