In order to solve the difficulties of the current BIM modeling and design software that can not meet the current demand for the delivery of informatization results, the slow progress of the forward design of municipal road BIM, and the inability to deal with the complex traffic organization scenarios such as the airport landside municipal road project, this paper carries out the research on the forward design of municipal road BIM based on the Guanglianda digital road BIM design platform. Based on the Guangzhou Baiyun International Airport Phase Ⅲ expansion project - landside municipal road project, the project has been applied with road component informatization, BIM forward design modeling and analysis, and automatic measurement of quantities. It is concluded that the digital dimension platform has high application value in fine modeling, quantity statistics, and results integration and delivery, It verifies the feasibility of BIM forward design in the whole process of municipal road engineering based on digital dimension platform. As a demonstration application of BIM model integration, engineering quantity auxiliary measurement, construction drawing output and multi-disciplinary collaborative design in municipal road, this research project plays a positive role in promoting the sustainable development of BIM forward design level in municipal transportation industry.