Transportation simulations require a corridor or region-wide traffic network with adequate resolution to properly depict vehicle movements and traffic dynamics. Usually, a transportation simulation or traffic analysis network is a subset of detailed commercial digital road network. It usually only includes higher-class roadways, such as freeway, ramps, highways, major arterials, etc. and excludes lower-class roadways, such as, minor or local streets. This widely accepted practice is partly based on that the local streets generally have no significance in serving commuting traffic in most cities. However, this proposition may no longer hold true in cities with dense network connectivity and the local streets cannot be ignored, like New York
