Research On Parallel Problems For Bus Lines And Urban Rail Transit

With the acceleration of China’s urbanization and the proposition of New Urbanization Construction Strategy, transportation infrastructure is playing a more and more important role in China’s economy and society development. A growing number of cities address transportation issues as a top priority in order to promote city image and boost economy. Under the guidance of ’Transit Priority Strategy’, urban rail construction constitutes a major part of modern city’s transportation infrastructure development. However, urban rail network cannot be formed overnight, the construction work calls for a long time commitment. For now, many cities in China are in the early stage of urban rail construction. It is usually observed that when the first urban rail transit line is operated, many cities fail to adjust former bus transit network structure accordingly due to the lack of experience. Especially, when a city owns a single urban rail transit line, the level of service would be relatively low. It results in a limited attraction radius and a weakened attraction ability. In this situation, people tend to overestimate rail line’s ’trunk effect’ and follow the rule to’cut the parallel line and add the vertical line’, Lines that are parallel to the urban rail transit line are then abandoned. As a result, citizens suffer travel inconvenience.By far, bus transit planning department takes the "social experience" practice to adjust bus lines after the opening of metro lines They keep the bus line open for a duration of time and observe the ridership variation, then decide whether this bus line will be removed or not. However, this practice wastes social resources, causes constant change of urban transit network structure and eventually transportation system disorder. Therefore, it is necessary to find a scientific method to predict the ridership variation of the corridor, and adjust parallel bus lines’route accordingly. In this way, after the metro line’s opening, a smooth transition of passenger flow can be expected. This thesis identifies main factors that influence the mode choice within the parallel lines’ corridor, based on land use type and citizens’travel survey statistics along the metro lines. It uses non-aggregate model to analyze flow pattern between bus transit and rail transit, ascertains transit structure in the future, and makes planning and decisions based on that. Finally, the thesis performs sensitivity analysis on main factors that influence mode choice in parallel lines problem, determines each factor’s influence degree and helps decision-makers to make the right call.The dissertation performs this method on Chengdu metro line1and bus line16, which are parallel to a great extent, and predicts transition rate on bus line16after metro line1is opened. Then the it gathers operational data before and after metro line1’s opening, compares the results calculated by the method, and confirms the validity of the proposed method.