The main cause of injuries and deaths during evacuation is impatience-triggered crowd behaviors. Thus, studying factors influencing crowd impatience is crucial. In this study, we proposed an impatience-based model to investigate the dynamics of crowd impatience during evacuations. Analyzing the effects of impatience self-growth and propagation rates on impatience levels and evacuation time reveals that the self-growth rate is the main determinant of impatience level. Both excessively high and low impatience levels lead to longer evacuation times. Moreover, the study analyzed the impact of exit widths on evacuation efficiency, revealing the optimal exit width varies based on the number of people. These findings provide insights into understanding the changes in crowd impatience during evacuation processes.