Both conflict resolution aid (CRA) and vertical situation display (VSD) systems may contribute to air traffic control (ATC) operations. However, their effectiveness still needs to be examined before being widely adopted in ATC facilities. This study aims to examine empirically the use of CRA and VSD as well as the systems’ interaction in ATC operations. It was found that CRA benefited conflict resolution performance by 13⋅7% and lowered workload by 46⋅4% compared with manually performing the task. The VSD could also reduce the air traffic controllers’ (ATCOs) workload and improve their situation awareness. Ultimately, when the first CRA failure occurred, the situation awareness supported by VSD offset the performance decrements by 30%. The findings from this study demonstrate that integrating VSD with CRA would benefit ATC operations, regardless of the CRA's imperfection.