The expressway can supply a capacity of above 25000 vehicles for cars per day and night averagely,and provide parted orientations and roadways for automobiles specially with controlling in and out. With the fast growth of the expressway mileage of our country, traffic volume of expressways also increasing, and some expressways being reconstructed from arterial roads, road surface and traffic facility of the majority of expressways are destroyed with different degrees. Maintenance and constructi...