Complex traffic situations and low driver perception are the leading contributing factors to traffic crashes. This paper explores speed cognitive skills of drivers on the effect of two types of expressway traffic environment, including a straight and flat filling section (Tianqiao section of G5 Expressway) and a tunnel section with the similar geometric parameters (Qinling mountain NO.1 tunnel of G5 Expressway). 8 participants were recruited to conduct a speed cognition experiment under the same controlled conditions, 246 groups of data were observed. The experiment results indicated that driver’s perception is different at different speeds, speed cognitive ability inside tunnel is better than that of outside tunnels under the condition with a great number of tunnel lamps to provide light sources. When accelerating dramatically after a long-time low-speed driving, the speed cognitive value gradually decreased along common section while increased inside tunnel. The research results can be used to analyze traffic safety in highway tunnel environments and assist engineers with safety facility allocation so as to improve speed cognitive ability of drivers to decrease accidents

: Human Factor, Speed Cognition, Expressway Tunnel, Driving Environment, Driving Behavior