State-of-the-art model to evaluate space headway based on reliability analysis

Stipulating a space headway is a pivotal concern in traffic engineering. Although consideration of a larger headway leads to safer traffic movement, consideration for a smaller headway can serve more traffic volume, which is significant from an economic standpoint. Implementation of a smaller headway, however, could lead to the tailgating phenomenon (short distances between two vehicles), which is perceived as troublesome and dangerous. Evaluating the space headway provides a reasonable approach to understanding the operational benefit for safety and traffic concerns. Using probabilistic analysis to account for uncertainty can be one of the best applicable methods because the headway data are not deterministic and are treated as random variables. More specifically, by emphasizing the reliability analysis, it is feasible to determine the appropriate space headway. The objective of this paper is to present a state-of-the-art approach for the evaluation of the statistical parameters of the headway by utilizing the reliability analysis. Several data sets among entire states were obtained from the Federal Highway Administration (FHWA) in 2012 and utilized in an analysis of a more pragmatic approach.