VEHICLE DELAY REDUCTION WHEN A SIGNALIZED INTERSECTION IS UPGRADED TO A SIMPLE DIAMOND INTERCHANGE

Trip time saving to users usually accounts for a large percentage of the total benefit of a transportation system improvement. In order to justify the upgrading of an at-grade signalized intersection to a simple diamond interchange, the evaluation and quantification of the saving in time becomes a necessity. This article describes a methodology to evaluate these time savings and, by using some generalized assumptions, an equation has been developed to calculate the reduction in vehicular delay once the approaching traffic volumes are known.