This research effort will provide information on how truck freight routing decisions are made and influenced by evaluating different data and information sources and implementing two primary data collection activities. This analysis will inventory/catalogue how routing decisions vary by 1) truck freight services type, 2) commodity shipped, and 3) industry sector served. It will include an assessment of how route choices are affected by factors such as urban congestion, travel time and route reliability, highway grade/elevation and curvature characteristics, business and product-specific supply chain characteristics, and other hierarchical routing decision rules. This knowledge will then be incorporated into the statewide freight model through improved impedence functions and routing logic and will be fully implemented when sub-national commodity flow information is available. This will improve statewide routing capabilities beyond minimum-distance or least-cost route algorithms and approach-routing logic that reflects actual freight shipping behavior. The research objective will be achieved through the following work tasks and activities.