Applied Mechanics and Materials Vols. 505-506

Abstract: A improved dynamic parameters model is presented based on cellular automata in this paper.The dynamic parameters: Direction-parameter, Empty-parameter and Cognition-parameter are formulated to simplify tactically the decision-making process of pedestrians, which can reflect the pedestrian judgment on the surrounding conditions and decide the pedestrians choice of action. Simulation of pedestrian evacuation and pedestrian moving rules were established, according to two-dimensional cellular automaton Moore neighborhood. In the improved model, the impact of the pedestrian density around exits is considered, the simulation and experimental results prove that this improvement makes sense, because besides the spatial distance to exits, people may also choose the exit according to the pedestrian density around exits. And the simulation results of improved model is compared with experiment, comparison shows that the improved model can reproduce the experiment well. The improved model is useful for further study, it is instructional significant for pedestrian evacuation, avoiding or reducing the number injuries.

Abstract: In foggy weather, contrast and color of images captured by traffic visual surveillance system are degraded significantly. To improve contrast and enlarge gray range of fog-degraded image, an improved filter variable multi-scale Retinex algorithm is presented. From comparing simulation resuts by four algorithms (global histogram equalization, local histogram equalization, multiscale retinex respectively variable filter retinex), the subjective and objective evaluation is summarized respectively. Experimental results show that the method has good universality and practicality to enhance local texture details of foggy image and suppress noise effectively.

Abstract: A good traffic signal design is one of the key solutions to many transportation problems. A two-way green wave control strategy for transit signal priority is reviewed and evaluated in this paper. Considering the traffic tidal phenomenon along the arterial roads during rush hours, a directional transit signal priority algorithm depend on the passenger flow has been developed for the coordination in signalized intersections. The algorithm provides signal timing plans for each intersection and the optimal bus speed along each section based on two-way bandwidth maximization. The strategy was designed to provide sectional control on transits, using electric signs and existing traffic control devices. In this paper, the strategys efficiency was evaluated using VISSIM micro-simulation along an arterial road which contains five intersections and serves more than ten bus lines. Actual data was used in the simulation. The simulation results show that the presented algorithm can effectively improve the operation efficiency of the transit system. This green wave control strategy reduced the number of stops by 34 % to 47 % and travel delay time by 27 % to 30% of the transit, while restricting the impact on vehicular traffic to the minimum. Moreover, the number of stops and travel delay time of vehicular traffic actually got a slight decrease. The algorithm shows promising results, and with minor upgrades, it can be applied to any type of intersection.

Abstract: The parking of vehicles in inhabited areas is a problem of majority of town with developed road traffic. The deficiency of parking place especially in town centers causes a lot of conflicts which influence the traffic flow continuity and traffic safety. Newly established parking places are usually occupied in short time and the problem is repeated. Trying to locate a lot of parking places on limited space of urban road results in various conflict situations when the vehicles parked along the road (lengthwise, perpendicularly or at angle) reach the roadway, the drivers enter the running lane during getting out of a vehicle or getting in a vehicle, etc. The paper presented brings results of analysis of conflict situations from such urban road with parking places along the road with use of video analysis. There are also presented designs for solutions of these problems with the purpose to increase the safety of all road participants.

Abstract: In order to evaluate traffic safety performance of continuous downgrades segment more accurately and quantitatively, a new safety evaluation method namely level of safety service (LOSS) is introduced. Based on the current traffic safety situation in China, the LOSS definition and classification method are studied systematically. In this paper, LOSS is built as a 5 levels framework and the graded threshold values are derived from accident frequency prediction models. The empirical research dataset includes 322 accidents data on a 15.27km continuous downgrades segment. The dataset is grouped into 16 fixed longitudinal grade sections to highlight the geometrical characteristics. Negative binomial model is best fitted among four candidate models, while the parameter estimation result indicates that geometrical factors, oversize vehicles mixed rate and average speed have significant positive effect on accident frequency. The overall LOSS of sample segment locates into the Level 3 interval, which means less safety performance than expected. As an extended application, LOSS specific to each fixed longitudinal grade section is analyzed.

Abstract: Crash Reduction Factor (CRF) is an important indicator for Economy Analysis of Safeguard Technology. This paper introduces the concept of CRF, and pointed out the limitations of its application. Meanwhile, it is necessary to adopt a variety of safeguard measures for multiple accident potential on a secton of highway in domestic mountainous rural road. Therefore, this paper presents the concept of general CRF. Then, multiple-event probability formula is proposed to calculate the generalized CRF for the feature of CRF. Finally. At last, discussed the work we needed to do if CRF was to be introduced into China.

Abstract: This paper presents a real road network case based on the time dependent vehicle routing problem with time windows (TDVRPTW), which involves optimally routing a fleet of vehicles with fixed capacity when traffic conditions are time dependent and services at customers are only available in their own time tables. A hybrid algorithm based on the Genetic Algorithm (GA) and the Multi Ant Colony System (MACS) is introduced in order to find optimal solutions that minimize two hierarchical objectives: the number of tours and the total travel cost. The test results show that the integrated algorithm outperforms both of its traditional ones in terms of the convergence speed towards optimal solutions.

Abstract: This study is aimed to establish how to organize the vehicles to exit from tunnels in a good order. First, the paper analyzed the traffic principles at the tunnel access. Then the organization design such as tunnel exits connecting crossroads、T style cross and vertical T style cross was introduced in detail and the lane connection feasibility was analyzed. Finally, the flow characteristics considering adjacent intersections were researched. The management methods of tunnel access may provide a preliminary support to improve the urban tunnel safety.

Abstract: With the rapid growth of car ownership, our travel is becoming more convenient; it also leads to a large number of road traffic accidents. The patterns of existing emergency rescue system for urban road traffic accidents are so conventional and slowly respond. This article focuses on the study of contingency mechanism and emergency rescue system for the rescue departments after the accidents, and puts forward new ideas for preventing urban road traffic accidents.

Abstract: Aiming to better network facility deployment and reduce cost, this paper proposed an optimization model for air traffic management airplane data communication network based on multi-objective nonlinear programming to optimize the communication network trunk node and analyze user subnetwork access. Using multi-objective decomposition method, a computer-aided resolution model is presented and then simulations proved its effectiveness. This model has theoretical instruction on air traffic management plane data communication network design, and can offer reference for relate studies.