Using Travel Time Measures to Estimate Mobility and Reliability in Urban Areas (9-1511-3)

There are several keys to developing and applying mobility measures that are technically useful and generally understandable. Travel time measures are relatively easy to comprehend, but they have not always been used because of data concerns, mandated reporting practices and other issues. Travel time and speed measures can serve many different uses, communicate to many different audiences and enhance the ability of project analysis techniques to determine the most appropriate set of policies, programs and projects for a situation. The overriding conclusion from any investigation of mobility and reliability measures is that there is a range of uses and audiences. No single measure will satisfy all the needs, and no single measure can identify all aspects of mobility or reliability - there is no "silver bullet" measure. The problems are complex and in many cases require more than one measure, more than a single data source and more than one analysis procedure. Mobility and reliability performance measures, when combined in a process to uncover the goals and objectives the public has for transportation systems, can provide a framework to analyze how well the land use and transportation systems serve the needs of travelers and businesses.