Ask the Experts–Developing Models That Consider Logistics Paths Used by Freight
Can models be developed that consider logistic paths used by freight?
An innovative mesoscale prototype model that is capable of considering the logistics paths used by freight has recently been developed for the Chicago Metropolitan Agency for Planning (CMAP).
The mesoscale model designed for CMAP is the middle layer of a three-layered approach to freight modeling that can examine commercial vehicle movements from the economic perspective of individual businesses that produce or consume goods. Since it is modeled at the disaggregate level, it can determine choices that impact transportation and logistics use, including supplier selection and path selection. The model uses the North American Industry Classification System to represent decisions of individual businesses in order to inform decision-making and includes truck, rail, water, and air modes, and handling facilities within logistics paths. This is accomplished through a four-step process:
- Firm Generation – Firms that produce/consume commodities are identified
- Supplier Selection – Trade linkages between individual businesses are formed through applying choice models at the individual business level.
- Flow Apportionment – High-level commodity flows between regions are disaggregated into total annual shipment volumes between suppliers and buyers.
- Path Selection –The transport and logistics paths are selected for transporting individual shipments from supplier to buyer.
The model considers logistics paths by creating additional logistics nodes that represent intermediate handling facilities such as airports, water ports, and rail intermodal yards.
This mesoscale model is therefore equipped to not only evaluate the selection of transportation and logistics paths, but also can provide the necessary data to comparatively analyze the attractiveness and utilization of existing and proposed logistics facilities. The transport and logistics paths are represented in a comprehensive fashion that uses a formulation to account for the simultaneous impact of each cost component on total cost on an annualized basis. This model will allow CMAP to develop and implement a more advanced model than all earlier frameworks to improve freight movement in the Chicago region.
Daniel Beagan is a Principal of Cambridge Systematics with more than 27 years of experience in transportation, traffic analysis, and planning in the public and private sectors. His experience also includes transportation forecasting, analysis, and development of mitigation for environmental impact reports in the office, retail, residential, university, industrial, and recreational industries.