To deal with the continous air traffic growth, air traffic controllers (ATCOs) are equipped with enhanced air traffic control (ATC) systems. The enhanced systems offer fully comprehensive aircraft information, such as plan view, speed, climb/descent rate, vertical information as well as the prediction of the aircraft parameters. Although increased information is often linked to the increase of situation awareness (SA), however, increasing the volume of information could also be detrimental to SA and workload. To what extend the aircraft information would benefit the ATCOs should be further investigated. This study aims to examine the effects of different information displays on ATCOs workload and SA. Thirty air traffic controllers (ATCOs) were divided into three groups corresponding to three display conditions: non-display, vertical, and trajectory display. The results revealed that the vertical display lowered ATCOs' workload and enhanced their SA as compared to other conditions. The workload and SA with the trajectory display were not different as compared to those in the existing ATC facility. It could be inferred that, on the one hand, with low information availability, ATCOs are required to interpret the airspace manually thus placing a cognitive burden on them. On the other hand, high information availability provided in the trajectory display condition, also hindered ATCOs from effectively using it due to the information overload. Here, the vertical display was found to provide sufficient information for ATCOs since it presents the information that was not depicted in the current radar system. Conversely, presenting information of all aircraft parameters was not necessarily valuable.