Search

Probabilistic yielding behavior is often observed at unsignalized crosswalks, but its impacts on the traffic flow in terms of traffic capacity and associated vehicular delay have not been examined before. The uniqueness of this problem is that neither traffic nor pedestrian flow holds the absolute priority as normally assumed in existing literature. Based on queuing theory, this paper developed traffic capacity and delay formulas considering the probabilistic priority. The proposed capacity equation reduces to the classic formula when the yielding rate equals one. The service time distributions for both queuers and non-queuers were derived, and M/G2/1 queuing model was applied to determine queue length and vehicular delay. Stochastic simulations showed that the proposed capacity and delay formulas precisely match the simulation results. For ease of practical applications, simpler queuing formulas including M/G/1, M/M/1 and M/D/1 were also examined. Noting that the differences between M/G2/1 and M/G/1 model are only marginal, especially for low yielding rates, we recommend theM/G/1 model for practical applications. In addition, when the pedestrian volume is relatively low, the M/M/1 model is also applicable due to its sufficient accuracy and simplicity. [ABSTRACT FROM AUTHOR] more...

This paper presents a method for defining and improving the traffic conditions in a set of cross section in the city of Cluj-Napoca, using microsimulation software for the traffic. Simulation models are designed to mimic the behavior of traffic in a time and space transport system in order to predict the system's performance. A simulation model studies a real world system, considering mathematical and logical concepts associated with the system operation and analyzes them using complex computer programming. Each simulation model presents a set of advantages such as: it can be more accurate than an analytical approach, it is able to test new conditions, it can improve the perspective concerning the significance of variables and of the way these variables interact. A case study is presented, using a set of three street intersections. In these intersections measurements of traffic during morning peak hours were performed. The measurements were acquired both manually and automatically, using time slots of 15 minutes each. The collected data was also used for model calibration. With the help of microsimulation software and a well-balanced model, information regarding traffic conditions can be found, resulting in analyses of the traffic evolutions. Some traffic conditions issues are identified and a set of improvement suggestions are presented. The measures proposed in this paper need to be tested and further optimized also by means of microsimulation, before being implemented, in order to obtain satisfactory results. The area under investigation exhibits quite large delays in traffic, in present-day conditions. This means smaller displacement speed, and, implicitly, more toxic emissions, that make the system be farther from the idea of sustainable transportation. [ABSTRACT FROM AUTHOR] more...

The spectacular increase of number of motor vehicles on the road is mainly attributed ingeneration oftraffic problems like accidents, congestions, delays etc., especially in the urban premises of developing countries. This paper examines the traffic problems and sustainable improvement ofroadintersection at Ettumanoor, India. The spacial and temporal constitutions of the vehicle as well as pedestrian traffic at the intersections were examined and the characteristics of the junction indoctrinating the delay problems are identified. Data regarding the traffic volume, land use and pedestrian movement activities are collected through direct field surveys. Analysis of the collected data revealed that the improper planning of the junctions, lack of traffic signals and unauthorised parking are the major factors contributing to the traffic congestions. Various remedial measures are also proposed, focusing on junction improvement, alternative operation plan and junction signalisation. [ABSTRACT FROM AUTHOR] more...