CARA is a human reliability assessment technique, which can be used to quantify human performance in the context of Air Traffic Management (ATM). This paper describes the CARA technique, including the data used for quantification, and the types of air traffic controller behaviours it quantifies, and the performance shaping factors it uses to modify task reliability. In order to evaluate CARA, it was applied in three actual ATM safety cases. The three safety cases related to an aircraft landing guidance system, a position/identity display for the air traffic control (ATC) aerodrome environment and an aerodrome procedure for low visibility conditions using future ATC systems. The performance of CARA in these applications is described.