为提高城市主干路交通流平均行程时间的估计精度,根据路段上游检测器采集的截面流量,建立了3种BPR(bureau of public roads)修正模型,包括全状态累积流量BPR修正模型、分状态标定的BPR模型和分状态累积流量BPR修正模型.仿真结果表明:全...为提高城市主干路交通流平均行程时间的估计精度,根据路段上游检测器采集的截面流量,建立了3种BPR(bureau of public roads)修正模型,包括全状态累积流量BPR修正模型、分状态标定的BPR模型和分状态累积流量BPR修正模型.仿真结果表明:全状态累积流量BPR修正模型明显优于传统的BPR模型;分状态标定的BPR模型和分状态累积流量BPR修正模型可以进一步提高估计精度,且后者可将阻滞交通状态下的平均估计误差降低至8.05%.展开更多
Based on the reliability budget and percentile travel time(PTT) concept, a new travel time index named combined mean travel time(CMTT) under stochastic traffic network was proposed. CMTT here was defined as the convex...Based on the reliability budget and percentile travel time(PTT) concept, a new travel time index named combined mean travel time(CMTT) under stochastic traffic network was proposed. CMTT here was defined as the convex combination of the conditional expectations of PTT-below and PTT-excess travel times. The former was designed as a risk-optimistic travel time index, and the latter was a risk-pessimistic one. Hence, CMTT was able to describe various routing risk-attitudes. The central idea of CMTT was comprehensively illustrated and the difference among the existing travel time indices was analyzed. The Wardropian combined mean traffic equilibrium(CMTE) model was formulated as a variational inequality and solved via an alternating direction algorithm nesting extra-gradient projection process. Some mathematical properties of CMTT and CMTE model were rigorously proved. Finally, a numerical example was performed to characterize the CMTE network. It is founded that that risk-pessimism is of more benefit to a modest(or low) congestion and risk network, however, it changes to be risk-optimism for a high congestion and risk network.展开更多
文摘为提高城市主干路交通流平均行程时间的估计精度,根据路段上游检测器采集的截面流量,建立了3种BPR(bureau of public roads)修正模型,包括全状态累积流量BPR修正模型、分状态标定的BPR模型和分状态累积流量BPR修正模型.仿真结果表明:全状态累积流量BPR修正模型明显优于传统的BPR模型;分状态标定的BPR模型和分状态累积流量BPR修正模型可以进一步提高估计精度,且后者可将阻滞交通状态下的平均估计误差降低至8.05%.
基金Project(2012CB725403-5)supported by National Basic Research Program of ChinaProject(71131001-2)supported by National Natural Science Foundation of China+1 种基金Projects(2012JBZ005)supported by Fundamental Research Funds for the Central Universities,ChinaProject(201170)supported by the Foundation for National Excellent Doctoral Dissertation of China
文摘Based on the reliability budget and percentile travel time(PTT) concept, a new travel time index named combined mean travel time(CMTT) under stochastic traffic network was proposed. CMTT here was defined as the convex combination of the conditional expectations of PTT-below and PTT-excess travel times. The former was designed as a risk-optimistic travel time index, and the latter was a risk-pessimistic one. Hence, CMTT was able to describe various routing risk-attitudes. The central idea of CMTT was comprehensively illustrated and the difference among the existing travel time indices was analyzed. The Wardropian combined mean traffic equilibrium(CMTE) model was formulated as a variational inequality and solved via an alternating direction algorithm nesting extra-gradient projection process. Some mathematical properties of CMTT and CMTE model were rigorously proved. Finally, a numerical example was performed to characterize the CMTE network. It is founded that that risk-pessimism is of more benefit to a modest(or low) congestion and risk network, however, it changes to be risk-optimism for a high congestion and risk network.
