Today, approaches and crossing islands are engineered with enhanced safety measures that are designed to keep cars and trains from meeting. Many of these enhanced measures are popular in newer railroad crossing applications, such as quiet zones and high-speed rail.

One of these enhanced safety measures is the four-quadrant gate crossing, in which four gates prevent access to the crossing from all lanes on both sides of the track. Four-quadrant systems operate dynamically: the entrance gates for both directions of travel descend when activated by an approaching train, preventing any further travel into the crossing island; the exit gates only descend when a vehicle detection system verifies that no vehicles remain in the crossing island, where they could be trapped if all four gates descended simultaneously.

Accurate, reliable vehicle detection is mandatory for a dynamic system like this to be effective. The Island Radar Quad Gate System offers FRA-approved, redundant broad-zone vehicle detection specifically for four-quadrant gate locations. Installed non intrusively in the track wayside, the Island Radar system provides a level of detection that is not feasible with other forms of detection. When configured to operate in dynamic mode with the exit gate management system controllers, the Island Radar system allows for complete safe clearance of the crossing island by placing the exit gates in a safe down position without trapping a vehicle on the island.  

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