Future airspace operations will allow flight crews to plan and fly their own preferred route and time of arrival without much intervention from air traffic control. This implies that pilots become more responsible for planning their own route while maintaining safe separation. This requires a strategic planning tool that support a high level of pilot Situation Awareness. Current aircraft are already equipped with terrain and traffic warning systems to, but these systems only provide short-term conflict resolutions. Recent studies have shown that a constraint-based approach to interface design could be used to support long-and medium-term decision-making and to provide a deeper understanding of the work domain. However, these studies were focused on either terrain or traffic. This paper aims to integrate both by showing the performance, traffic and terrain overlays on an experimental Vertical Situation Display. In a simulator evaluation, in which twelve professional airline pilots participated, this Vertical Situation Display was compared to a baseline Vertical Situation Display that only showed a terrain overlay and intruder aircraft relative to own ship. The experiment results revealed that the performance, traffic and terrain overlays improved pilots' overall situation awareness and pilots rated their workload lower. Regarding decision-making, however, the results were not significantly better. Regarding safety, there were less traffic conflicts, but more ground proximity intrusions.