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40 CHAPTER 4 Freight Mobility Constraints This chapter also presents analysis of information gathered Lack of connectivity between freight modes, congestion- from interviews and survey. Based on the analysis, this chap- laden networks, lack of technology or equipment--all of ter defines freight mobility constraints, potential causes, and which would hinder efficient freight traffic flow. performance indicators for monitoring and measuring the Any internal or external factors that define the limits on the constraints. This chapter also discusses the different types of amount of freight that can be moved between two points effi- constraints from multimodal perspectives. ciently, safely, and in an environmentally acceptable way. These factors include the characteristics of the physical infra- structure, operational procedures, and regulatory regimes. 4.1 Defining and Characterizing Any factor or factors connected with highway operations Freight Mobility Constraints that significantly add to the cost of moving freight, e.g., Results from the interviews and survey conducted as part of delay, truck operating costs due to congestion and terrain, this project indicated that there is no formal definition of a undersized intermodal facilities. freight mobility constraint. Such a definition or taxonomy is lacking among all modes both from public-sector and private Based on this range of possible definitions, a freight mobil- industry perspectives. Freight mobility constraint is defined in ity constraint may be generally defined as a physical or infra- different ways, but all definitions have a common theme. The structure deficiency, regulatory action, or operational action that following are some of the definitions: impedes or restricts the free flow of freight either at the network level or at a specific location. Mobility constraints create addi- Any infrastructure, institutional, financing, operational, or tional costs or affect service levels negatively. environmental deficiency that impedes--or has a significant A freight mobility constraint can be caused by physical, likelihood of impeding--the safe and efficient movement of operational, or regulatory or policy factors. These categories of goods in a sustainable manner. constraint types or causes are defined below. Freight mobility constraints are operational, infrastructure, or institutional issues that prevent the free/unencumbered Physical Constraints--any geometric or infrastructure con- flow of freight. ditions that constrain freight operators from operating at Any event, situation (e.g., construction, customs/border designed, safe speeds, and within legally required parameters delays, weather-related road closures), or physical feature Operational Constraints--practices, events, or occurrences such as a physical design deficiency that impacts the move- that constrain system throughput, and constrain optimal ment of freight. and legal operating conditions Impediments or obstacles, including infrastructure, reg- Regulatory Constraints--Federal, state, or local regulatory ulations, or congestion, that prevent freight from moving requirements that restrict the flow of freight through the freely, quickly, and efficiently anywhere in the trans- system. portation system between the origin and destination of the shipment. The following sections discuss the causes of freight mobil- Any system limitation, policy decision, operational concern, ity constraints encountered on highways, railways, and at or communication issue that undermines the potential flu- deepwater ports and inland waterways. Examples of the three idity of any segment of the logistics stream. categories of constraints are also presented.