This research investigated the suitability of non-track-circuit-based technologies as a cost-effective means to deploy active warning devices at passive grade crossings.  While several promising technologies were identified, some of the findings were unexpected.  Mainly, there existed a subset of passive grade crossings that may potentially experience a sharp decrease in risk if these crossings were to be equipped with active warning devices.  This finding was based on an analysis of the societal benefits accrued from equipping the crossings with active warning devices relative to the installation and life-cycle costs during the expected lifetime of the equipment.

The cost differential between track-circuit-based and non-track-circuit-based systems was minimal and could not be used alone to justify alternative train detection technologies.  However, alternative technologies were superior to track-circuit-based systems at locations prone to flooding/snow/ice, leaf buildup on rails, and accrual of rail rust.  This finding further suggested that there was a compelling argument for evaluating alternative grade crossing train detection technologies.