Résultats de recherche pour « Traffic simulation »

Many universities are evaluating ways to improve mobility while dealing with increased demand for parking within the campus. Different types of parking strategies are considered as potential tools for improving campus mobility and meeting increased parking demand. Limited information is available on how removing on-street parking from the center of a university campus, relocating motorists to park on the periphery of campus, will impact the neighboring transportation system. Although dynamic traffic assignment (DTA) is a valuable tool for evaluating such impacts, most previous studies have used DTA with mesoscopic models. Thus, there is also limited guidance on the application of DTA within microscopic simulation models. The purpose of this study was to test a novel methodology for evaluating the mobility impact of relocating parking. The authors developed a method of utilizing DTA within a microscopic traffic simulation model. This model was applied to a case study capturing the changes in traffic patterns and volumes as a result of university parking changes. The authors found the methodology efficient and repeatable, and identified several simulator challenges with this new application. The case study findings suggest that, due to the significant number of motorists searching for the high-demand parking in the core of campus, relocating this parking to periphery lots will reduce the average travel time, even when accounting for the increased walking time.

Passenger waiting time in a lobby and ride time in a car give a good indication of the service capability of an elevator group. If several cars are in the same group, these parameters are too complicated to model in a closed form. In this paper, procedures for modelling elevator performance and passenger traffic in a generic building are described. Elevator dynamics and control, call allocation and passenger traffic modelling are described. Simulated interval and load values are compared with theoretical results, and variances in simulation results are investigated. According to typical simulation results, there is no direct connection between interval and passenger waiting times, as is often assumed. The interval depends on the elevator bank configuration and elevator performance capabilities. Performance indicators, such as the number of starts and cycle times, become saturated even at low traffic intensities. The waiting times, in addition to elevator performance, depend on the passenger traffic patterns and, during heavy traffic, service level is greatly affected by the call allocation algorithm.

This study analyzed traffic congestion scenarios in underground roads diverging and merging sections and underground sections that run parallel to ground roads using a microscopic traffic simulation model. The appropriate ratio of the ramp inflow or outflow of traffic volume to the entry traffic volume at the starting section of the underground road network was analyzed. Furthermore, the effect of traffic operation such as adequate throughput, average traffic speed, occupancy, and volume versus capacity (V/C) ratios before the occurrence of traffic congestion in all three road networks was properly produced. To maintain a minimum level of service of all underground sections at the D–E level, the underground inflow traffic volume should be equal to approximately 70% of the 4000 pcph inflow traffic volume from an open road to the underground. The results of this study are a useful reference for establishing traffic control application standards to minimize underground traffic congestion. They also provide useful insights for underground road design.

Traffic lights are available in almost all cities and towns worldwide. They solve many traffic congestion problems, save numerous human lives and avoid frequent automobile accidents. Optimizing the operation of traffic light systems in roads is essential for any city's economy, safety and environment. Simulation technology is probably the best tool to analyze and optimize the operation and design of traffic light systems. The increasing use of automobiles in cities has lead city administrators and local governments to install traffic lights and detectors in large quantities in order to avoid accidents and optimize the movement of automobiles and humans. Although signalization can solve traffic conflicts at the intersections, it causes stoppage. The chief objective of optimal traffic control is to improve system mobility and throughput at reduced delays. Delays and stops are not only irritating and pricey to drivers and passengers, but they also add to air contamination and energy use. In this paper, we analyze and demonstrate how the timings of a traffic light system are calculated in order to determine the optimum and proper timings needed to optimize traffic flow.

The present state of the art of simulating traffic problems is reviewed in outline, and part of a briefly annotated bib liography of the work done on traffic simulation is pre sented. The full 206-item bibliography (available from the author) covers discrete event simulation of such situations as intersection and network flows, and also more general techniques such as 'car-following' models. Transportation survey techniques—such as assignment and distribution- are not specifically covered.