An Enhanced Advance Loop Placement Method for Dynamic Dilemma Zone Protection at High Speed Signalized Intersections

At high speed signalized intersections, advance loop detectors are typically placed upstream the intersection to provide protection for yellow light dilemma zone (DZ). However, most widely used advance loop placement methods are typically based on the old study results and traditional computation of static DZ. To reflect DZ dynamics in loops placement, a new method specifically designed for dynamic DZ protection is urged to be developed. In this context, an alternative loops placement method which is developed based on the updated model of dynamic DZ is proposed and is evaluated with comparison to three classic loops placement methods. The results prove that the alternative method is superior to the classic Bonneson, Beirele, and SSITE layouts in terms of reducing DZ conflicts, intersection delay, and max-out occurrence percentage. It greatly enhances both safety and operation by providing effective and efficient protection for dynamic DZ.