Search results for "traffic"
showing 10 items of 598 documents
Calculation of Turbo-Roundabouts with Slip Lanes
2013
A turbo roundabout is a particular type of roundabout where all lanes are bounded by traffic signs and by non-mountable curbs installed at entering and circulating lanes. Turbo roundabouts also have a very particular shape to accomplish the splitting of traffic streams and to prevent cars weaving through. These aspects make turbo-roundabouts more appropriate than roundabouts when a higher level of safety has to be guaranteed, particularly in presence of relevant pedestrian and two-wheels traffic volumes. Only in some traffic conditions, turbo roundabouts can offer higher capacities than conventional double-lanes roundabouts, so if more capacity must be guarantee a bypass lane can be added t…
Evaluation of the Safety Performance of Turbo Roundabouts by Means of a Potential Accident Rate Mode
2015
Turbo roundabouts are a particular road intersection layout, designed to increase the safety of double-lane roundabouts, while maintaining their excellent capacity. The main feature of this new concept of roundabout is the impossibility to move from one lane to another, provided by physical barriers marking the lanes. The paper shows an application to turbo roundabouts of a potential accident rate model, aiming to evaluate their safety improvement. Themodel is based on the concept of potential conflict: each vehicle involved in a general intersection performs a series of maneuvers which potentially imply a crash, according to the actual traffic. The number of accidents related to each criti…
Agent-based test-bed for road information systems
2012
Road safety is one of the most important concerns of road authorities. In order to improve road safety, traffic managers develop traffic management and control strategies. The use of advanced traffic management systems is to support road managers in daily traffic management tasks. However, it is important to test in advance, the traffic strategies to evaluate the results and their suitability to the current situation. In this study, a test-bed based on multi-agent is presented. The purpose of this test-bed is to be able to test several traffic information strategies in case of adverse weather situations. It consists in a knowledge model implemented by a set of basic agents. These agents are…
Analysis of Approaches to Internet Traffic Generation for Cyber Security Research and Exercise
2015
Because of the severe global security threat of malwares, vulnerabilities and attacks against networked systems cyber-security research, training and exercises are required for achieving cyber resilience of organizations. Especially requirement for organizing cyber security exercises has become more and more relevant for companies or government agencies. Cyber security research, training and exercise require closed Internet like environment and generated Internet traffic. JAMK University of Applied Sciences has built a closed Internet-like network called Realistic Global Cyber Environment (RGCE). The traffic generation software for the RGCE is introduced in this paper. This paper describes …
Developing Passenger Car Equivalents for Freeways by Microsimulation
2015
Abstract In this paper a method of estimation of the passenger car equivalents for heavy vehicles on freeway is described. The variation in traffic quality was evaluated basing on a traffic demand characterized by different percentages of heavy vehicles. Aimsun micro-simulator was used to isolate traffic conditions difficult to capture on field, to replicate them to have a number of data as much as possible numerous, and to quantify the fundamental variables of traffic flow, namely the speed, flow, density, for a test freeway segment. Model calibration was accomplished by using traffic data collected at observation sections on the A22 Brenner Freeway, Italy. In order to check to what extent…
Risk Indicators and Road Accident Analysis for the Period 2012–2016
2017
Road accidents are a major societal issue for every country. The purpose of this paper is to assess the number of traffic and road accidents depending on a series of variables (collision mode, road configuration, conditions of occurrence, road category, type of vehicle involved, personal factors, and length of time of the driving license) in Romania from 2012–2016. The analysis of the road accident trend identifies the causes of accidents, road safety performance indicators, and risk indicators. Having these identified data, a framework is proposed for improving the road safety system and reducing accidents. The Romanian Police, the National Institute of Statistics (NIS) in Romania, and the…
ANALYSIS OF DIFFERENT VISUAL STRATEGIES OF 'ISOLATED VEHICLE' AND 'DISTURBED VEHICLE'
2017
This paper analyses the driver’ visual behaviour in the different conditions of ‘isolated vehicle’ and ‘disturbed vehicle’. If the meaning of the former is clear, the latter condition considers the influence on the driving behaviour of various objects that could be encountered along the road. These can be classified in static (signage, stationary vehicles at the roadside, etc.) and dynamic objects (cars, motorcycles, bicycles). The aim of this paper is to propose a proper analysis regarding the driver’s visual behaviour. In particular, the authors examined the quality of the visually informa-tion acquired from the entire road environment, useful for detecting any critical safety condition. …
How to derive the analytical capacity model for not-conventional urban roundabouts
2008
The inapplicability of current methods for analyzing operations of urban not-conventional roundabouts (i.e. not referable to standard schemes) hampers seriously the assessment of their operational performances. Moreover, local constraints and the road network structure have produced lots of geometric layouts that make hard to propose an only framework to explain performances of not-conventional roundabouts. Also for these intersections it is hoped to have scientifically based methods to analyze operations with a proper reliability. Starting from these considerations, the paper shows the conceptual path followed to analyze operations at not-conventional roundabouts along an arterial of Paler…
Microsimulation-based passenger car equivalents for heavy vehicles driving turbo-roundabouts
2016
Due to its geometric design, turbo-roundabouts impose greatest constraints to the vehicular trajectories; by consequence, one can expect a more unfavourable impact of heavy vehicles on the traffic conditions than on other types of roundabouts. The present paper addresses the question of how to estimate Passenger Car Equivalents (PCEs) for heavy vehicles driving turbo-roundabouts. The microsimulation approach used revealed as a useful tool for evaluating the variation of quality of traffic in presence of mixed fleets (different percentages of heavy vehicles). Based on the output of multiple runs of several scenarios simulation, capacity functions for each entry lane of the turbo-roundabout w…
Mobility Patterns and Mode Choice Preferences during the COVID-19 Situation
2022
The empirical research on the COVID-19 epidemic’s consequences suggests a major drop in human mobility and a significant shift in travel patterns across all forms of transportation. We can observe a shift from public transport and an increase in car use, and in some cases also increase of cycling and (less often) walking. Furthermore, it seems that micromobility and, more generally, environmentally friendly and comanaged mobility (including shared services), are gaining ground. In previous research, much attention was paid to the mode choice preferences during lockdown, or early stages of the SARS-CoV-2 situation. The blind spot, and aim of this work, is how long observed changes in mode ch…