| Freight movement is an essential and growing part of the urban transportation system. The importance of freight movements is surely of growing interest to transportation planners. However, data on freight flows are costly and difficult to obtain. Based on existing research on freight transportation models, this paper proposes a non-survey freight modeling system that offers a low-cost way to estimate detailed freight flows from secondary data sources. The approach has been implemented to estimate regional truck freight traffic flows on a large metropolitan area's network. The freight data derived in this way are simply estimates, but they are available at low cost and easily updatable in comparison to expensive freight origin-destination survey. The freight data have been loaded onto a regional highway network along with conventionally obtained passenger flow data to yield relatively accurate simulations of highway network performance. Geographical Information Systems (GIS) methods are applied to improve non-survey freight modeling system with respect to systems operation and model validation. |
