Air pollution at many types of intersections and other roadside``hot spots'' is not accurately characterized by state-of-the-practice models. In this study, data were collected on trac¯ows, second-by-second CO and NO 2 ambient concentrations in Shanghai, China. The sampled data were compared with CAL3QHC modeling results. We found that: (1) intersection hot spot emission concentrations were explained primarily by queuing activities of motor vehicles; (2) air quality concentrations are dicult to predict because of complex dispersion processes near high-rise buildings; and (3) screening models such as CAL3QHC are prone to large errors in dense cities with mixed trac and high-rising buildings. Suggestions are made for improved models relevant to dense developing cities. Ó

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Abstract. The high-speed railway and common speed railway subsystems as important components of the railway transportation system, can make railway traffic organization more orderly, when there are a rational division and balance development between them. In order to quantitatively evaluate the coordinate relations between high-speed railway subsystem and common speed railway subsystem, this paper takes the railway transportation corridor from Baoji to Lanzhou as an example. Firstly, using Logit model and grey forecasting model predict the passenger volume, passenger turnover and time value of high-speed railway and common speed railway in the Baoji-Lanzhou corridor. And then, the coupling forecast model of these two subsystems is established. Lastly, the coupling and coupling coordination of these two subsystems using are predicted and analyzed at theatrically level. IntroductionAt present, predecessors have done a lot of researches which are related the transport internal system and other systems' coupling relationship. ZAMBELLI[1] and CREPIN.A.S[2] introduced the coupling theory to study the coordination degree between subsystems. Shuai Bin et al [3] divided China regional economy into three types through studying coupling relationship between regional economy and the railway development. Zhu Lei[4] by combining coupling degree and coordination degree, building coupled coordination degree model analyzed the coupling and coordination relationship among various traffic modes of the corridor. Li Xin et al [5] used the coupling function to analyze the relationship between the China railway transport situation and opencast coal mine production, but the paper used analytic hierarchy process in the coupled model for weight calibration, which was influenced by subjective factors greatly, and might reduce the accuracy of assessment. Zhang Yaodong [6] took the urbanization and transport systems as the two main indexes, and built the coupling degree model to study traffic modes in Lanzhou and the coupling mechanism of urban development. Yang Li et al [7] took the Xinjiang as an example and built the coupling degree model of the Xinjiang transportation infrastructure and economic to analyze their coupling mechanism, but the paper did not divide the index weights.Based on the previous experience, this paper constructed a coupling evaluation model of high speed railway and the common speed railway in Baoji-Lanzhou corridor, and does make a brief forecast and analysis on the coupling degree and coupling coordination of two traffic modes in the next ten years. The result has guide significance for planning the two systems' rail transport corridors development.