Making the Most of an Existing System through Access Management at Major Arterial Intersections

Abstract

The intersections of major arterials are designed to facilitate the conflicting movements of numerous vehicles in a manner that is both safe and efficient. Accesses located within the functional area of major arterial intersections complicate intersection activity because additional conflicts arise from ingressing and egressing movements at the accesses. This research analyzed the impact of accesses on crashes within the functional area of major arterials. The effects of access spacing within functional areas and access setback from intersections were addressed. The functional areas of 144 signalized major arterial intersections across the state of Utah were examined. A database was developed and contained the frequency, type, and severity of functional area crashes as well as the intersection and roadway characteristics within the functional area. Statistical analyses were conducted to determine the influence of accesses on crashes within the functional area of intersections. The statistical analyses showed that the existence of accesses within the functional area was correlated with increased crashes and crash severity costs. In particular, an increase in commercial access density was associated with increases in crash totals, crash rates, and rear-end crashes in intersection functional areas. The analyses also showed that study intersections meeting Utah Department of Transportation corner clearance standards exhibited fewer right-angle crashes and lower crash severity costs. Adherence to such standards improves safety and increases efficiency of the transportation network and thus aids jurisdictions throughout the nation in making the most of the existing infrastructure.