Based on the findings of a recent field study, Nodine (2011) reported that 88% of forward collision warning (FCW) system alerts in that study were accurate when the lead vehicle was moving. Similarly, 86% of lane departure warning (LDW) alerts activated accurately when the vehicle departed its lane without signaling. However, safety benefits are only realized when the system is both accurate in identifying a crash imminent situation and when the warning presented to the driver elicits a timely and appropriate response (braking or steering). The National Highway Traffic Safety Administration (NHTSA) is conducting studies under the Crash Warning Interface Metrics (CWIM) program to develop valid and sensitive “distracted driver” protocols for the evaluation of the driver vehicle interfaces (DVIs) of FCW and LDW systems on test tracks and in driving simulators as well as examining potential safety-related effects of consistent DVIs for these warning systems. CWIM focuses on distracted drivers because distraction-affected crashes represent a substantial crash risk, including 9% of the fatal crashes and 18% of injury crashes that occurred in 2010 (NHTSA, 2012). The DVI consists of the displays of the warning system, including the warning itself and associated system status displays. Although controls and settings are available for some systems, their usability and effectiveness are outside of the scope of the CWIM program. In this paper, we review some of the prominent results and methodological issues encountered in studies conducted under the CWIM program and describe how they are addressed in the work that is currently underway.