This research develops a validated prototype truck traffic network model for North Carolina. The model includes all counties and metropolitan areas of North Carolina and major economic areas throughout the U.S. Geographic boundaries, population and employment define the study areas. The network is based on the National Highway Planning Network and it includes Interstates, US Highways, and secondary roads. The North Carolina network attributes include highway type, speed, and terrain. The base year long haul truck data is based on FHWA Freight Analysis Forecasting origin-destination data for North Carolina including origins and destinations outside North Carolina. Short haul traffic and back haul truck traffic are generated using simplified trip generations rates and adjustments to the FAF data. Base year 2006 truck traffic estimates for North Carolina are validated by over 450 truck traffic counts throughout the state. Only ADTT (average daily truck traffic) is estimated by the network model, not total vehicle traffic including automobiles. Since the model does not include automobile trips and truck-only traffic is usually far below roadway capacity, the current network model is not built with a capacity-constrained traffic assignment feature. The network is sensitive to input speed but not to traffic volumes on the highway. Consequently any network changes for scenario testing have to be expressed in terms of speed changes to the network links affected.
