Porous asphalt pavement is a part of the permeable pavement system, which can be used to mitigate the negative impacts of urbanisation on the water hydrological cycle and environment. This study aims to assess the mechanical and hydrologic characteristics of porous asphalt pavements, with and without geocell composites, using a plate load test, falling weight deflectometer test, and rainfall simulation test. The corresponding results indicate that the elastic modulus of the unreinforced pavement is lower than that of the reinforced pavement. The analysis demonstrates that the use of geocell composites effectively increases the load-bearing capacity of the pavement. When the base layer is reinforced with geocells, its load-bearing capacity increases. Observation of the rainfall simulation tests on the reinforced pavement indicates that the reinforced pavement effectively handles the surface runoff.

The fuel is not injected when the driver releases acceleration pedal of a vehicle with engine speed higher than about 1,500rpm in mid driving speed range. This is called ‘fuel-cut function’ and almost every modern vehicle is equipped with this function. This fuelcut function is activated on downhill parts of a highway most often. Therefore the vehicle-exhausted CO₂ can be zero in these downhill parts if the driver could recognize these parts of highway. We compared the vehicle-exhausted CO₂ emission with and without fuel-cut function in this study. The exhausted CO₂ mass of a passenger car(2,000cc engine volume) is reduced by about 4% with this function in a test highway of South Korea. This CO₂ reduction effect can be achieved if the downhill parts of a highway are painted with a specific color. And this road painting can be included in the highway road rehabilitation policy to cut down CO₂ emission of vehicles.