Research on Water-Related Issues in Urban Road System

The urban road system is not only one of the most important urban infrastructures but also the important composition of urban ecological system. The road systems in many cities are suffering from various water-related problems, such as road water logging, increased drainage load resulted from concentrated runoff, waste of rainwater resource due to failure replenishing of the surface runoff to the groundwater system during the rainstorm period. The road waterlogging would affect its traffic function, even result in temporary regional traffic gridlock, and impair the quality and service life of the road works. The road surface runoff could contaminate the surrounding water environment, and under disturbance of vehicle wheels the dust accumulated on the road would pollute urban air when drying up. The analysis showed that the water-related problems are mainly resulted from manmade factors such as low design standard of road drainage system, poor environmental protection facilities for rainwater storage and infiltration, high-raised green belt, and the weaknesses of road building technology. Countermeasures were proposed, such as raising road drainage standard, innovating and popularizing road building materials and technology, and lowering the elevation of the green belts. Case study showed that the application of the pervious asphalt concrete as paving material and the adoption of lowering green belts, could significantly ease the street water logging, reduce the runoff pollution and urban drainage load, and improve the rain resources utilization.