Search results for "Traffic flow"

Applications to Traffic Breakdown on Highways

2004

During the last years researches into properties of vehicle ensembles on highways form a new branch of physics, called physics of traffic flow. On macroscopic scales the vehicle ensembles exhibit a wide class of phenomena like phase separation and phase transformations widely met in physical systems. Due to the steadily increasing traffic volume in cities and on highways, the mathematical modelling of these phenomena has attracted a great interest. Particularly, the topic of car—following has become of increased importance in traffic engineering and safety research.

Improving performance of roundabout intersections by optimizing traffic-flow speed

2017

Streamlining of urban traffic influence nowadays almost everything about our modern life. The main effect, which we all feel as the daily traffic participants, either as pedestrians or vehicles drivrers, is travel time to work and back. Roundabouts intersections have a number of advantages over intersections with traffic lights, they reduce the severity of accidents, traffic speeds to provide an “calmer” road environment. So, operating performance of roundabouts are complicated, influenced by the confluence operations. The paper aims at analyzing the current situation of traffic in two crowded roundabouts in Sibiu, comparing the results with the original data and proposing solutions to impr…

Acceptance of truck platooning by professional drivers on German highways. A mixed methods approach.

2020

Abstract Truck platoon driving is a current branch of automated driving, which has the potential to radically change the work routine of professional drivers. In a platoon system, one truck (semi-)automatically follows a lead truck with a reduced distance, which produces significant savings in fuel and enables better traffic flow. In a current application of truck platoon driving, the following vehicle operates at level-2 automation. Thus, the driver of the following truck merely has to supervise the semi-automated system, which takes over steering and speed control when engaged. Level-2 truck platoon driving had not been tested with professional drivers in real traffic before. We hypothesi…

Passenger Car Equivalent for Heavy Vehicles Crossing Turbo-roundabouts

2016

Abstract Turbo-roundabouts represent an innovative scheme of modern roundabouts which provides a spiraling traffic flow and requires drivers to choose their direction before entering the intersection, since raised lane separators mark the lanes on the ring. The configuration of the turbo-roundabout makes that patterns of conflict at entries with one and two conflicting traffic streams can coexist. This paper presents research efforts aimed at measuring quantitatively the effect of heavy vehicles on operational conditions of a turbo-roundabout. The study starts from the initial belief that the greatest constraints to the vehicular trajectories imposed by the turbo-roundabout necessarily impl…

Nonlocal Second Order Vehicular Traffic Flow Models And Lagrange-Remap Finite Volumes

2011

In this paper a second order vehicular macroscopic model is derived from a microscopic car–following type model and it is analyzed. The source term includes nonlocal anticipation terms. A Finite Volume Lagrange–remap scheme is proposed.

Zero-range model of traffic flow.

2005

A multi--cluster model of traffic flow is studied, in which the motion of cars is described by a stochastic master equation. Assuming that the escape rate from a cluster depends only on the cluster size, the dynamics of the model is directly mapped to the mathematically well-studied zero-range process. Knowledge of the asymptotic behaviour of the transition rates for large clusters allows us to apply an established criterion for phase separation in one-dimensional driven systems. The distribution over cluster sizes in our zero-range model is given by a one--step master equation in one dimension. It provides an approximate mean--field dynamics, which, however, leads to the exact stationary s…

Funzionalità e sicurezza di intersezioni stradali urbane. Un intervento progettuale nel campus universitario di Palermo

2008

Embedding “roadside equipment” into environmental assessment of transportation system: the case of safety barriers

2015

The work arises from the consideration that the environmental impact of a road cannot be limited to the analysis of its constituent materials, even if correctly analyzed in their life cycle. In fact, a given road not only consists of the pavement and subgrade, but also includes several different components and accessories (e.g. road marking, drainages, safety barriers, etc.) that contribute to set a road infrastructure in operative conditions. As a matter of fact, only limited attention has been paid in the scientific literature to roadside components, unlike pavement and traffic flow. In the present work, the environmental burden of one of these components, i.e. the safety barrier, has bee…