Guide to establishing monitoring programs for travel time reliability.

This guide describes how to develop and use a travel time reliability monitoring system (TTRMS). It explains why such a system is useful, how it helps agencies do a better job of managing network performance, and the actions a traffic management center must take to establish a TTRMS. The Guide was prepared under Project L02 within the Strategic Highway Research Program 2 (SHRP 2) under the management of the Transportation Research Board. Travel time reliability is the absence of variability in travel times. If a system is reliable, people can get to where they want to go, when they want to be there, all the time. For example, if a freeway is reliable, then its travel times are the same for the same condition, all year long. It is similar to a vehicle that always starts when the key is turned on. Of course, in reality no system or roadway is perfectly reliable, and unexpected events (e.g., incidents) sometimes significantly reduce the reliability of a system. This executive summary describes the structure of the Guide; briefly addresses the questions of the necessity, function, and structure of a TTRMS; and provides an illustration and overview of implementation. The Guide is organized into the following major parts: * The executive summary, which gives agency managers a description of a TTRMS explains why it is valuable and how it can be used. The summary is intended to prepare such individuals for the input they will receive from their staff and help them make informed decisions about future actions. * A 5-chapter guide that describes the process of measuring, characterizing, identifying, and understanding the effects of recurrent congestion and non-recurrent events that affect travel time reliability. * Four appendices that provide more detailed information on the functional specifications of a monitoring system, methodological details, a series of case studies, and a series of use cases (applications). Project L02 also has a separate final report that documents the research that led to the Guide. (Author/publisher)