Potential Freeway Congestion Severity Measure: Impact of Continuous Congestion Patterns

To better understand the characteristics of traffic congestion and efficiently employ congestion measures for interstate highway systems, this study examined the limitations of the congestion measures currently in use such as the percent of congestion and the duration of continuous congestion. Based on this study, these congestion measures provided different results of the congestion severity for even the same interstate highway segment, which means that the use of a single measure might not give a reliable evaluation result. In order to minimize the potential bias and enhance the advantage of each congestion measure, this study proposed a composite congestion severity measure by combining congestion information of both percent of congestion and duration of continuous congestion measures. The writers found that the proposed composite congestion severity measure efficiently identified the levels of the congestion severity of interstate highway segments and that it could be instantly accomplished with the existing loop detector count systems in most states. This proposed measure may be a potential candidate for describing levels of congestion severity and can provide a proper guideline for transportation engineers or decision makers to efficiently allocate available budget and resources to correct applicable interstate segments.