Integration of the human factors literature on rear-end crash causation with that of rear signaling and lighting, yields a conceptual categorization of potential advances. The paper addresses methodological human factors questions on how to strike a balance between minimizing nuisance signals and maximizing effective signals. Scenarios, characterized by vehicle motion, the drivei’s actions and/or the environment are discussed:​

I. Braking at low speed or stationary

II. Decelerating with no braking

III. Sudden accelerator pedal release

IV. Anti-lock braking system automatic activation

V. Braking at any speed For each scenario, human factors issues imply potential signals and functions. This paper helps in setting the foundation for an extensive evaluation program of advanced rear signaling and lighting systems.