In order to determine the regulations of the development of taxi supply under entry regulations in Chinese cities, an improved neural network model is applied to find the particular years when the government artificia...In order to determine the regulations of the development of taxi supply under entry regulations in Chinese cities, an improved neural network model is applied to find the particular years when the government artificially puts new taxis into the market, and then extract the political influence from the taxi supply. The model is also utilized to study the relationships between the adjusted taxi supply and non-policy factors. A case study of Nanjing city is conducted. The results show that 2001 and 2007 are the particular years that the Nanjing government artificially put new taxis into its taxi market, which is in accordance with the five-year plan of China and the local development plans. The results also show that the improved neural network model has a good performance in expositing the evolution of adjusted taxi supply related to non-policy factors.展开更多
Comparative analyses were conducted to compare the effects of the behavioral characteristics of the drivers of taxis and private cars on the capacity and safety of signalized intersections. Data were collected at sixt...Comparative analyses were conducted to compare the effects of the behavioral characteristics of the drivers of taxis and private cars on the capacity and safety of signalized intersections. Data were collected at sixteen signalized intersections in the Nanjing area in China. The risk-taking behaviors of the drivers of taxis and private cars were compared. The results suggest that 19.9% of taxi drivers have committed at least one of the identified risky behaviors, which is 2.37 times as high as that of the drivers of private cars(8.4%). The traffic conflicts technique was used to estimate the safety effects of taxis and private cars. The overall conflict rate for taxis is 21.4% higher than that for private cars, implying that taxis are more likely to be involved in conflicts. Almost all of the identified traffic conflicts can be attributed to certain levels of risk-taking behaviors committed by either taxi drivers or the drivers of private cars, and taxi drivers are more likely to be at fault in a conflict. Failure to yield to right-of-way and improper lane change is the leading causes of the conflicts in which taxis are at-fault. The research team further studied the effects of taxis on the queue discharge characteristics at signalized intersections. The results show that the presence of taxis significantly reduces both start-up lost time and saturation headways. The effects of taxis on saturation flow rates are dependent on the proportion of taxis in the discharge flow, and the saturation flow rates increase with the increase in the proportion of taxis. The adjustment factors for various proportions of taxis for different turning movements are then calculated to quantitatively evaluate the effects of taxis on the capacity of signalized intersections.展开更多
The taxi drivers' cruising pattern was learned using GPS trajectory data collected in Shenzhen,China.By employing zero-inflated Poisson model,the impacts of land use and previous pick-up experience on cruising dec...The taxi drivers' cruising pattern was learned using GPS trajectory data collected in Shenzhen,China.By employing zero-inflated Poisson model,the impacts of land use and previous pick-up experience on cruising decision were measured.The cruising strategies of different types of drivers as well as the top one driver were examined.The results indicate that both land use and previous pick-up experience affect travel behavior with the former's influence(7.07×10-4 measured by one of the coefficients in zero-inflated Poisson model) being greater than the latter's(4.58×10-5) in general,but the comparison also varies across the types of drivers.Besides,taxi drivers' day-to-day learning feature is also proved by the results.According to comparison of the cruising behavior of the most efficient and inefficient driver,an efficient cruising strategy was proposed,that is,obeying the distribution of land use in choice of cruising area,while learning from pick-up experience in selection of detailed cruising location.By learning taxi drivers' cruising pattern,the development of measures of regulating travel behaviors is facilitated,important factor for traffic organization and planning is identified,and an efficient cruising strategy for taxi drivers is provided.展开更多
基金The National Basic Research Program of China(973 Program)(No.2012CB725400)
文摘In order to determine the regulations of the development of taxi supply under entry regulations in Chinese cities, an improved neural network model is applied to find the particular years when the government artificially puts new taxis into the market, and then extract the political influence from the taxi supply. The model is also utilized to study the relationships between the adjusted taxi supply and non-policy factors. A case study of Nanjing city is conducted. The results show that 2001 and 2007 are the particular years that the Nanjing government artificially put new taxis into its taxi market, which is in accordance with the five-year plan of China and the local development plans. The results also show that the improved neural network model has a good performance in expositing the evolution of adjusted taxi supply related to non-policy factors.
基金Projects(51322810,50908050)supported by the National Natural Science Foundation of China
文摘Comparative analyses were conducted to compare the effects of the behavioral characteristics of the drivers of taxis and private cars on the capacity and safety of signalized intersections. Data were collected at sixteen signalized intersections in the Nanjing area in China. The risk-taking behaviors of the drivers of taxis and private cars were compared. The results suggest that 19.9% of taxi drivers have committed at least one of the identified risky behaviors, which is 2.37 times as high as that of the drivers of private cars(8.4%). The traffic conflicts technique was used to estimate the safety effects of taxis and private cars. The overall conflict rate for taxis is 21.4% higher than that for private cars, implying that taxis are more likely to be involved in conflicts. Almost all of the identified traffic conflicts can be attributed to certain levels of risk-taking behaviors committed by either taxi drivers or the drivers of private cars, and taxi drivers are more likely to be at fault in a conflict. Failure to yield to right-of-way and improper lane change is the leading causes of the conflicts in which taxis are at-fault. The research team further studied the effects of taxis on the queue discharge characteristics at signalized intersections. The results show that the presence of taxis significantly reduces both start-up lost time and saturation headways. The effects of taxis on saturation flow rates are dependent on the proportion of taxis in the discharge flow, and the saturation flow rates increase with the increase in the proportion of taxis. The adjustment factors for various proportions of taxis for different turning movements are then calculated to quantitatively evaluate the effects of taxis on the capacity of signalized intersections.
基金Project(50908099)supported by the National Natural Science Foundation of ChinaProject(201104493)supported by the Doctoral Program of Higher Education of China
文摘The taxi drivers' cruising pattern was learned using GPS trajectory data collected in Shenzhen,China.By employing zero-inflated Poisson model,the impacts of land use and previous pick-up experience on cruising decision were measured.The cruising strategies of different types of drivers as well as the top one driver were examined.The results indicate that both land use and previous pick-up experience affect travel behavior with the former's influence(7.07×10-4 measured by one of the coefficients in zero-inflated Poisson model) being greater than the latter's(4.58×10-5) in general,but the comparison also varies across the types of drivers.Besides,taxi drivers' day-to-day learning feature is also proved by the results.According to comparison of the cruising behavior of the most efficient and inefficient driver,an efficient cruising strategy was proposed,that is,obeying the distribution of land use in choice of cruising area,while learning from pick-up experience in selection of detailed cruising location.By learning taxi drivers' cruising pattern,the development of measures of regulating travel behaviors is facilitated,important factor for traffic organization and planning is identified,and an efficient cruising strategy for taxi drivers is provided.
