In order to solve the problem of rainwater discharge in expressway service areas, low-impact development (LID) facilities are arranged systematically in an expressway service area in China. A storm rainwater management model is applied to simulate the hydrologic process so as to analyze the influence of a bioretention area on rainfall runoff regulation under three LID situations: separate bioretention, bioretention and permeable pavement in-series, and bioretention, permeable pavement, and grass swales in-series. Based on the results, increasing the ratio of bioretention area to drainage area increases the average values of runoff reduction rate, runoff peak reduction rate, and runoff peak delay time under five types of rainfall. The results indicate that permeable pavement can significantly reduce the hydraulic load of bioretention while grass swales have little effect. Under different rainfall levels, the runoff reduction rate of the LID service area increases by 16.16–68.41%, the runoff peak reduction rate increases by 49.31–59.07%, and the runoff peak delay time increases by up to 326 min compared with a traditional service area.