Assessing air traffic complexity on a mid term horizon can help to timely identify those safety-critical encounter situations that would require many tactical resolution maneuvers to be resolved. This is particularly useful in advanced autonomous air traffic management systems, where aircraft are responsible for self-separation maintenance. In this paper, we propose a new method to evaluate mid term traffic complexity based on the aircraft intent information and current state. The key novelty of the approach is that uncertainty in the future aircraft positions is explicitly accounted for when evaluating complexity.