摘要: |
Our previous work has developed a distributed framework for network-wide traffic monitoring and platoon information aggregation using vehicle-to-vehicle communications alone (1), which is the foundation of an envisioned virtual traffic operations system that could supplement existing operation systems or serve as an alternative in extreme situations. The performance of the distributed monitoring system depends on both the market penetration rate and the spatial distribution of equipped vehicles in the road network. The latter is affected by traffic dynamics. Traffic signal controls at intersections play a significant role in governing traffic dynamics and will in turn impact the distributed monitoring system. The objective of this study is to investigate such impacts. With the presence of traffic signal controls, signal timing plans as event data should be considered for evaluating the performance of the distributed traffic monitoring and platoon information aggregation system. Among various traffic control factors, such as the operation mode of a traffic controller and signal timing parameters, we choose g/C ratio as one of the possible key factors. The performance of the monitoring framework is investigated with different g/C ratios under multiple traffic scenarios. The simulation results show that a positive correlation exists between the accuracy of speed estimation and the g/C ratio. If a traffic signal is present (g/C<1), downstream coverage ratio usually increases with the g/C ratio as well. While the upstream coverage ratio and the relative error in density do vary with g/C ratio, the variation is not significant and no distinct trends are observed. This indicates that the density estimation is more robust, and it may be desirable and possible to enhance the speed estimation method utilizing density information to achieve higher accuracy. Moreover, since accurate traffic monitoring sets the foundation for advanced traffic control strategies, we argue it is important to consider the resulting performance of traffic monitoring, together with other mobility measures when designing intersection control mechanisms. |