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The rapid development of new urbanization boosts the pace of urban rail transit (URT) network construction. The new-built lines not only facilitate people's daily travel, but also change the reliability of the original network. In this paper, based on the complex network theory, the static characteristics of Tianjin URT represented by the current and forward networks are analyzed. The global efficiency is selected as the evaluation index to analyze the evolution characteristics of the network. The results show that Zhigu station and Xiawafang station are more vulnerable in the current network, while Zhangxingzhuang station and Jinzhonghe street station are the key stations in the forward network, and need to be paid more attention. Meanwhile, the lines M9 and Z2 as the key lines in the long-term network and their reliability must be ensured. [ABSTRACT FROM AUTHOR]

The unique valley geographical environment and the congestion-prone road landscape make valley city traffic jammed easily. In this paper, under the background of "open blocks", two open patterns, which correspond to two different road landscapes ("ideal grid opening" and "open under realistic conditions"), are proposed. Taking Lanzhou city as an example, six basic statistical characteristics are used to compare and analyze the changes of road network topology in blocks to find out which open pattern is more suitable for valley cities. The results show that the pattern "open under realistic conditions" has a significant effect on the improvement of network performance and capacity. Specifically, breaking the "large blocks" and developing the small-scale blocks help to alleviate the traffic pressure. Besides, the opening of blocks located along river valley has a more positive effect on improving road network performance than the blocks sited in the inner area of cities. [ABSTRACT FROM AUTHOR]

With the development of autonomous driving technology, autonomous vehicles (AV) will gradually replace human-driven vehicles (HDV), but it will still be a mixed traffic flow of autonomous vehicles with different levels of automation for a long time. In addition to cars, trucks regarded as moving bottleneck are also an important part of traffic flow of expressway. In this paper, the elimination rule of moving bottleneck is introduced into the traffic flow model, and the improved hybrid traffic flow cellular automata model is proposed. Next, through numerical simulation, the existence and influence of moving bottleneck caused by heavy duty trucks are hypothesized and verified. The simulation results show that with the proportion of trucks increases, the influence range of moving bottleneck expands, resulting in the decrease of capacity and traffic congestion. Then, the impact of Level 2 autonomous vehicles (hereinafter referred to as L2 AVs) on the traffic flow of moving bottlenecks is explored. The simulation results show that with the proportion of L2 AVs increases, traffic capacity increases, and traffic congestion ratio at medium and high density decreases. Under medium density, the average velocity fluctuates greatly, while under high density, the average velocity decreases due to limitation of density. In summary, L2 AVs can alleviate influence of moving bottlenecks, increase traffic capacity, improve traffic congestion, and lift road safety. The cellular automata model of traffic flow including moving bottleneck proposed in this paper is based on the actual road situation, considering the fact that most of autonomous vehicles on the expressway currently are L2 AVs, and moving bottleneck is mainly caused by heavy trucks. This research contributes to an in-depth analysis of L2 AVs on heterogeneous traffic flows under moving bottleneck environment. • The recognition rules of moving bottleneck are proposed. • The impact of L2 AVs on heterogeneous traffic flow involving heavy trucks and human-driven vehicles is explored. • The congestion caused by heavy trucks running in parallel can be effectively alleviated by L2 AVs. [ABSTRACT FROM AUTHOR]

This article aims to explore the stability, energy consumption and CO 2 emissions of a novel discrete car-following model with time delay. Under the assumption that the preceding two successive vehicles can realize the communication through V2V (Vehicle to Vehicle) communication environment. Moreover, the time-delayed average optimal velocity difference control scheme is also considered. Based on the proposed discrete car-following model, error dynamical system is formulated and asymptotic stability is developed. The sufficient condition for the time-delayed average optimal velocity difference control scheme of the discrete car-following model with time delay is obtained, the asymptotic stability is ensured. In addition, numerical simulations are constructed and further illustrated the cooperative driving by V2V communication can improve stability, reduce energy consumption and CO 2 emissions of traffic system. Moreover, the time-delayed average optimal velocity control scheme is also conductive to improve stability, reduce energy consumption and CO 2 emissions of traffic system. • A discrete-time car-following model with time delay is proposed. • The delayed average optimal velocity difference control is considered. • The stability is developed and stability condition is obtained. • The effects of time delay and control scheme on dynamics are studied. [ABSTRACT FROM AUTHOR]