Traffic flow state analysis required detection vehicle sampling quantity obtaining method

This invention relates to an obtaining method for sampling volume of detection cars needed by analyzing traffic flow state including: 1, pre-processing data of a GPS detection car, 2, matching the car with a GIS map, 3, obtaining mean velocity of highway sections, 4, obtaining sampling volume of a road net detection car, which traces vehicles to eliminated interference data, applies a nearest method to match maps then uses a space time curvature fitting model to get a mean velocity of directional sections, calculates historical data of the GPS detection car, its mean number of weight and empty in each time section network of a day, applies a sampling formula to compute the sample frequency of each time section and get the sample volume of the detection car of the road network finally.