Improvement in the quality control method to distinguish the black spot of the road

This text shows several differentiating methods and the quality control method is improved.Since the stat character of the accident frequencyμ which takes record is not analyzed,the precision of the results of the method is decreased.Some literature is consulted which takes n_b and 1/t_bas the parameters of the GAMMA distribution to compute the equal accident rate λ,which make λ rational and the result exact.Finally,it takes the example of Shen-da expressway to analyze the Black Spots using the method and achieves the rational result.