Benefits of Split Intersections

Abstract

As urban and suburban intersections become more congested, a likely remedy for recurring traffic jams is grade separation in the form of diamond or tight diamond interchanges. A more economical intersection configuration to relieve congestion has been built overseas. The major highway is separated into two-directional, one-way roads comparable to an at-grade diamond junction known as the split intersection. The split intersection facilitates smoother flows with less driver delay, mainly by reducing the number of required signal phases from four to three. The success of converting to the split intersection has been analyzed by using deterministic methods that showed increased capacity and noticeable reduction in delay. The analysis methodology relies on a microsimulation technique to predicate previous claims and provide economic benefits. Comparisons of vehicular delay between the single and the split intersection revealed substantial savings in travel delay, particularly for higher entering volumes and higher left-turning movements. The findings provide guidance to planners and designers on the expected benefits of converting a four-lane by four-lane single intersection to the split intersection.