Traffic simulation

About: Traffic simulation is a research topic. Over the lifetime, 6211 publications have been published within this topic receiving 95004 citations.

Adaptive cruise control design for active congestion avoidance

Abstract: We present an adaptive cruise control (ACC) strategy where the acceleration characteristics, that is, the driving style automatically adapts to different traffic situations. The three components of the concept are the ACC itself, implemented in the form of a car-following model, an algorithm for the automatic real-time detection of the traffic situation based on local information, and a strategy matrix to adapt the driving characteristics (that is, the parameters of the ACC controller) to the traffic conditions. Optionally, inter-vehicle and infrastructure-to-car communication can be used to improve the accuracy of determining the traffic states. Within a microscopic simulation framework, we have simulated the complete concept on a road section with an on-ramp bottleneck, using empirical loop-detector data for an afternoon rush-hour as input for the upstream boundary. We found that the ACC vehicles improve the traffic stability and the dynamic road capacity. While traffic congestion in the reference scenario was completely eliminated when simulating a proportion of 25% ACC vehicles, travel times were already significantly reduced for much lower penetration rates. The efficiency of the proposed driving strategy even for low market penetrations is a promising result for a successful application in future driver assistance systems.

Traffic Flow Theory

Abstract: This monograph which is primairly addressed to graduate students in traffic engineering, is also intended to be a reference book and an introduction to traffic flow theory in general The 10 chapters of this book cover aspects of measurement, statistical distributions, models, information processing, noise and simulations The various methods of measurement currently available to the traffic engineer are considered, and the definitions of characteristics are related to these methods of measurement Methods of averaging are also considered The quantities to statistical distributions of various traffic characteristics are considered, as well as the uses of distributions Models that relate pairs of the basic traffic flow characteristics (speed/flow, speed/ concentration etc) are examined, as are models that consider travel time as one of the variables Insight is provided into the way drivers use the information they receive It is shown that although a driver is continuously making decisions, his control actions are limited to control of heading and control of acceleration Car following and acceleration noise is considered, and acceleration noise is developed as a measure of the quality of traffic flow Models that have been developed for fluids are applied to traffic continuity equations for fluids are developed Studies are described which have been used to improve flow through tunnels and explain traffic behavior at bottlenecks, and the continuum and car-following theories are unified A Boltzman-like theory of traffic is briefly discussed The chapter on queueing models, presents some of the results of studies of served, delays at intersections and unsignalized intersections Simulation of traffic flow by digital computers is detailed

Modelling vehicle interactions in microscopic simulation of merging and weaving

Abstract: This paper presents data, collected from video-recording, on the microscopic details of merging and weaving manoeuvres under congested traffic conditions. Based on these observations, a classification of the manoeuvres into free, forced and cooperative lane changes is proposed. A new lane change model is developed, incorporating explicit modelling of vehicle interactions using intelligent agent concepts. The model was implemented in the ARTEMiS traffic simulator, and several hypothetical test studies were conducted to demonstrate the capabilities of the new model. The results show that the model is able to reproduce the observed behaviour of individual vehicles in terms of speed, gap acceptance and conflict-resolution in all three types of lane change manoeuvres, and hence, it is able to simulate highly congested flow conditions in a realistic manner. The macroscopic results in terms of speed-flow relationship are close to the typical expected results. The model can simulate both freeways and signalised urban arterial networks.

A network flow model for lane-based evacuation routing

Abstract: Most traffic delays in regional evacuations occur at intersections. Lane-based routing is one strategy for reducing these delays. This paper presents a network flow model for identifying optimal lane-based evacuation routing plans in a complex road network. The model is an integer extension of the minimum-cost flow problem. It can be used to generate routing plans that trade total vehicle travel-distance against merging, while preventing traffic crossing-conflicts at intersections. A mixed-integer programming solver is used to derive optimal routing plans for a sample network. Manual capacity analysis and microscopic traffic simulation are used to compare the relative efficiency of the plans. An application is presented for Salt Lake City, Utah.

Modelling lane changing and merging in microscopic traffic simulation

Abstract: This paper introduces Simulation of Intelligent TRAnsport Systems (SITRAS), a massive multi-agent simulation system in which driver-vehicle objects are modelled as autonomous agents. The simulation outputs can be used for the evaluation of Intelligent Transport Systems applications such as congestion and incident management, public transport priority and dynamic route guidance. The model concepts and specifications, and the first applications of the model in the area of incident modelling in urban arterial networks were described in previous publications. This paper presents the details of the lane changing and merging algorithms developed for the SITRAS model. These models incorporate procedures for ‘forced’ and ‘co-operative’ lane changing which are essential for lane changing under congested (and incident-affected) traffic conditions. The paper describes the algorithms and presents simulation examples to demonstrate the effects of the implemented models. The results indicate that only the forced and cooperative lane changing models can produce realistic flow-speed relationships during congested conditions.