By adding bilateral elevated layers, the renovation and expansion of the expressway have improved the traffic capacity, but a subsequent rise in problems, such as insufficient spacing, excessive traffic volume, and multi-diversion, has made the existing traffic signs fail to meet the drivers’ guidance needs. In response to this issue, this study took the Ji-He Expressway in Shenzhen as an example and designed four optimized traffic sign schemes of interchange based on the conventional standard scheme, and developed the corresponding stereoscopic compound expressway scenes by the Unity3D engine. The vehicles on the expressway will drive out of the ground-level road at the first diversion, enter the elevated-level road at the second diversion, and connect to other expressways at the third diversion. 28 drivers simulated driving in different scenes using external interactive devices, and their driving behavior data such as speed, acceleration, lane position, etc., were obtained. By calculating the point-by-point significance of indicators within each affected section in different guidance sign design schemes, differences in spatial dimensions of each indicator were presented, and further analysis shows that 3 km warning signs can help drivers perceive the situation of the ramp ahead as early as possible. Lane guidance signs can improve the longitudinal and lateral stability of vehicles at the ramp, and drivers can take better lane changing strategies. Navigation voices assistance can improve the driver’s speed control proficiency, lane changing awareness of expressway exits, and psychological comfort at the interchange of stereoscopic compound expressway. The research shows that Unity3D has high fidelity, good interactivity, and low cost, and it can provide technical support for relevant research on driving behavior in complex road scenes in the future. At the same time, this study also provides a theoretical reference for the establishment of traffic guidance signs in expressway renovation and expansion projects.