Assessing Strengths and Limitations of a Statewide Tour Based Freight Model Using Scenario Analysis in Maryland
Corresponding Author: Sabyasachee Mishra, University of Memphis
Presented By: Sabyasachee Mishra, University of Memphis
Abstract
As part of the Strategic Highway Research Program (SHRP2) Implementation Assistance Program C-20 grant a behavior based freight model was developed for Maryland. The model adopts a multi-layer structure where freight flows and the resulting vehicles movements at the local level are informed by and sensitive to changes at the upper level. For example, changes over time in the freight flows to and from a region influence the demand for long distance truck travel, but also the need for additional local truck movements to facilitate local deliveries and pickups of shipments. The model represents the complete supply chain of good movements flowing into and out of the model region. This includes global suppliers and buyers who produce imports and consume exports, as well as business establishments across the country. That structure supports scenario testing to understand the impacts of changes in the economy over time, including different patterns of long haul domestic flows and imports and exports as domestic and international trading partners change. The model also moves from a traditional trip-based approach to a more realistic tour-based approach, where the travel patterns of trucks are modeled to mimic the routings that dispatchers and drivers develop. These more realistic travel patterns are inherently more responsive to the effects of congestion in the transportation system. While the developed model is at its initial stages, three scenario analysis tests are conducted to assess the strength and limitation of the model for planning applications. The three scenario tests include (1) freight network impacts because of shared and collaborative urban deliveries, (2) freight diversion of potential commodities to non-truck modes, and (3) capacity enhancement of potential long distance non-urban corridors to alleviate congestion from urban corridors. The first scenario analyzes freight supply chain and infrastructure impacts of recently built Amazon’s 1 million square feet fulfillment center on Broening Highway Maryland. The second scenario determines the reduction in truck flows when potential commodities use non-truck modes. The third scenario presents truck diversion from a congested I-95 urban corridor to US-385 corridor to alleviate congestion between two beltways in the Baltimore-Washington region.