Calculating the contribution rate of intelligent transportation system for the smooth general characteristic of urban traffic

At present, a lot of cities in the world are using intelligent transportation system to relieve urban traffic problems, some big cities in China also invested a lot of material resources in the intelligent transportation system, but what the affect the intelligent transportation system can make to urban traffic is still can´t be explained. Therefore, this article takes Guangzhou´s intelligent transportation system as the research object, studying from the smooth general characteristic of transportation, extracting the indicators that effect traffic smooth general, and using the difference in difference model to calculate the contribution rate of the intelligent transportation system for smooth general characteristic, and then according to the calculated results to explain the mechanism that the intelligent transportation system for urban transportation´s smooth general characteristic.