In judicial practice, there has been a significant controversy in regard to the application of law in cases of pedestrians illegally entering the expressway and whether expressway operators should take the responsibility, and, if so, on what basis. The doctrine of liability fixation and the specific calculation of compensation are both inconsistent. Through empirical research and theoretical analysis, we define express transportation as a highly dangerous activity, but the expressway is not an area of absolute high-risk activity. Thus, the identification of a high-risk activity area should be carried out according to relative circumstances. Only when a pedestrian illegally enters onto an expressway can the expressway be recognized as a high-risk activity area, and the expressway operator should take a big proportion of responsibility for the high-risk activity. At this stage, the expressway operator should take a presumption of aggravated offense. In such accidents, expressway operators and the third party are responsible for the accident and should take proportionate liability or the incomplete supplementary responsibility that is non-recoverable according to their respective faults or whether the third parties can provide compensation in an objective manner.