Operations and Capacity Strategies for Preserving and Enhancing Highway Functionality

摘要

The functionality of the nation‟s transportation system relies on the traffic operationalperformance of roadway segments and intersections. It is imperative to consider functionality inall stages of a highway‟s lifecycle and to protect, preserve, and where possible enhancefunctionality during the course of planning, operations, and maintenance practices and functions.Despite the extensive efforts to improve highway functionality, roadways in many areasexperience extended periods of congestion. Much of the congestion is attributable to operationsand capacity deficiencies, such as ineffective or inefficient traffic control, underutilization ofalternative travel modes, poorly maintained or outdated traffic signals, or facility design thatdoes not meet current operational needs.Recognizing the importance, Texas Department of Transportation (TxDOT) initiated acomprehensive research project to examine what losses to state highway functionality occur overtime, the causes of those functionality reductions, and actions that can be taken to preserve,recover, and enhance functionality over time. This paper presents findings of the researchrelevant to operations and capacity. The paper also presents an in-depth case study throughwhich the research team investigated in detail how the functionality of a major freeway evolvedin all aspects and associated practices, policies, and programs. The products of the associatedresearch and the findings presented in this paper serve as valuable guidelines for state and localtransportation agencies to select a proactive approach in preserving and enhancing thefunctionality of the transportation system.