Abstract: The taxi GPS trajectories involve sufficient temporal and spatial characteristics and make it easy for us to obtain potential knowledge for understanding human mobility pattern and urban traffic network dynamics. Sensing urban traffic conditions not only enables traffic management authority to improve urban traffic management. It can also provide decision-making for residents and taxi drivers. A spectral clustering method is proposed for sensing traffic congestion using taxi GPS trajectories. First, taxi GPS trajectories are pre-processed and matched with the urban road network established based on the primal graph representation. Second, the average speed of the road segments is obtained according to the taxi GPS trajectories and a dynamic weighted graph of urban road network is constructed to capture complicated urban traffic network. Then, a spectral clustering method is developed to detect the urban traffic congestion. Finally, the congestion evolution characteristics in Lanzhou, China are visualized and analyzed during different periods in the weekdays and weekends. Experimental results show that the proposed method can effectively detect traffic congestion, and the results are consistent with the usual actual experience. Compared with other traffic congestion methods, the proposed method can detect urban traffic congestion with wider coverage and lower cost. Therefore, the proposed method can be integrated into the classic intelligent traffic system, assisting urban traffic prediction, personal travel route plan, route planning and navigation application.Abstract: The taxi GPS trajectories involve sufficient temporal and spatial characteristics and make it easy for us to obtain potential knowledge for understanding human mobility pattern and urban traffic network dynamics. Sensing urban traffic conditions not only enables traffic management authority to improve urban traffic management. It can also provide d...Show More
Abstract: Côte d'Ivoire has based its economic development on export-oriented agriculture of primary products (coffee, cocoa). The strong economic growth, called The «Ivorian Economic Miracle» of the years 1970 was supported by transport infrastructures and roads in particular. The extensive degradation of national roads has impacted negatively on the country's economic growth. This present study analyzes the contribution of roads to Ivorian national growth, mostly that of the sub-component: roads maintenance. The econometric study on time series is conducted using Eviews, and takes the actual maintenance budgets actually executed per capita as proxy for road investments. The results of short and long-term estimates show Ivorian private and public investments, exports and the labor force highly contribute to national growth, thus they are important channels of Ivorian growth. The negative impact of the budget really realized per capita on GDPR (-4.6%) thus demonstrates the effect of reducing roads to growth in Côte d'Ivoire. This confirms the hypothesis that the poor state of roads contributes to the country's declining growth. For Ivorian roads contribute positively to the national economy. We have determined thresholds for roads maintenance investments compared to national public and private investments, respectively 901.18% and 93.06%. These thresholds improve the contribution of roads maintenance at 79.65% and 64.62%proportionally to public and private investments. In order to enable roads to contribute positively to Côte d’Ivoire’s economic growth, the Ivorian state must index the executed budget to public or private investment in proportion to the thresholds set above.Abstract: Côte d'Ivoire has based its economic development on export-oriented agriculture of primary products (coffee, cocoa). The strong economic growth, called The «Ivorian Economic Miracle» of the years 1970 was supported by transport infrastructures and roads in particular. The extensive degradation of national roads has impacted negatively on the countr...Show More