Actual Traffic Situation Research Articles

Integrating Topographical and Topological Data in the Estimation of the Actual Traffic Situation on Airports

The main necessary functions to manage the traffic on the movement area and the airspace around an airport are surveillance, control, routing and guidance.1 Routing is often also termed planning. Today these functions are carried out manually by the controller in the tower and in the apron. But automatic assistance is becoming more and more important with increase of traffic flow in order to reduce the controllers’ workload from routine work. The basis for assisting systems is normally a system to estimate the actual traffic situation.

FhG-Co-driver: From map-guided automatic driving by machine vision to a cooperative driver support

A digital road map provides partial knowledge about the operating environment for a road vehicle. If a road vehicle is equipped with a video camera, machine vision approaches can provide knowledge about the actual traffic environment around the vehicle. Experiences with a combination of two such approaches during the commissioning of a van for automatic driving on a private road network are reported, including experiences gathered during subsequent driving experiments on public roads and several improvement cycles for hardware and software. Based on these experiences, a second generation vehicle for automatic driving—a sedan—has been designed and commissioned. It is currently evaluated on public roads. This equipment provides an experimental platform for studying driver-vehicle interactions with the option to automatically evaluate actual traffic situations around the vehicle in real-time. Our equipment thus offers an approach to record and disentangle the multitude of factors which influence the—often subconscious—reactions of a driver. It is our working hypothesis that only an automatic, in-depth understanding of the actual traffic situation facilitates the design of a driver support system which is competent and flexible enough to win acceptance by a wide spectrum of users.

Performance bounds for power control supported DCA-algorithms in highway micro cellular radio systems

To achieve a high spectrum efficiency in cellular radio systems, the radio resource allocation algorithms have to be adaptive to the actual traffic and interference situation. The focus of the paper is on performance bounds of a cellular radio system using dynamic channel assignment (DCA) combined with power control (PC). A trivial upper bound on the performance is identified. The bound is given by the performance of a hypothetical system which is able to use all channels simultaneously in all cells. A lower bound on the performance is derived from a theoretical PC supported DCA-algorithm. For a highway micro cellular system and a deterministic propagation model, numerical results show that the lower and upper bounds are tight. That is, the results indicate that it is possible to use all channels in all cells simultaneously and still provide an acceptable signal-to interference ratio in all assigned communication links.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

System Components for Driver Support by Evaluation of Image Sequences

Based on experiences by commissioning two experimental vehicles, a system architecture for investigating driver assistance approaches is described. If a road vehicle is equipped with a video camera, machine vision approaches can provide knowledge about the actual traffic situation around the vehicle, e.g. obstacles. Taking into consideration the complexity of traffic situations, a modelling approach for traffic scenes is necessary which is based on the instantiation of generic situation schemata within an interpretation cycle by utilizing sensor information about driver, vehicle and environment.

State of the Art in Dynamic Traffic Management in the Netherlands

Dynamic Traffic Management (DTM) is the management of traffic streams, of vehicles and of the demand for traffic, with the help of data on the actual traffic situation as well as on the predicted situation. Reliable, real-time data is essential for correct information to drivers and for control of traffic. Monitoring systems are given a high priority in The Netherlands. The different DTM-tools considered in the Dutch approach are grouped according to their effect either on travel demand, modal split or a specific travel mode. The tools are important with a view on reducing the negative impact of traffic on the environment. Traffic management serves this objective by controlling the remaining traffic as effective as possible. This paper describes the results of completed orcurrently running pilot-projects.

An Assessment of Measures to Predict the Outcome of Driving Evaluations in Patients With Cerebral Damage

The evaluation of the ability of patients to return to driving after cerebral damage stands out as one of the most important tasks confronted by rehabilitation professionals. The present study was designed to critically assess evaluations that were developed at one facility to determine fitness to drive: an offroad, predriver evaluation of skills regarded as important in driving and an on-road, behind-the-wheel evaluation of abilities needed to drive in actual traffic situations. The evaluation results of 3-patients with cerebral damage due to traumatic head injury or cerebrovascular accident were studied retrospectively. Only 4 out of 21 items on the predriver evaluation significantly predicted the outcome of the predriver evaluation and none of the predriver evaluation items predicted the outcome of the behind-the-wheel evaluation. Only 6 of the 26 tasks on the behind-the-wheel evaluation significantly predicted the outcome of the behind-the-wheel evaluation. None of the items on the predriver evaluation or the behind-the-wheel evaluation explained a significant portion of variance related to outcome. The lack of internal and predictive validity of driver evaluations is discussed in light of these findings, and recommendations are given for improving the predictive power of driving evaluations.

The concept of risk and behaviour models in traffic psychology

Abstract There are only a few theories which can be used as a basis for research and practice in traffic psychology. Accident proneness has long been considered antiquated. Risk homeostasis is also problematic and, at best, applicable to a very limited domain. Although the analysis of road traffic by system theory is to be welcomed, attention should be drawn to the fact that this hardly permits conclusions about driver behaviour in the actual traffic situation. Prognosis based on theories of general psychology is also only restrictedly possible. Theories of learning explain the formation processes of behaviour in traffic, but are not qualified to predict specific actions which take place in spite of and contrary to learned behaviour patterns. Other models could be considered, but they can only explain certain aspects (i.e. perception, motivation, social aspects). A comprehensive theoretical concept in traffic psychology is therefore necessary. Driving in the actual traffic situationshould be the main issu...

The air traffic flow control problem as an application of network theory

In this paper the air traffic flow control is approached as a constrained optimization problem on a multicommodity network. The proposed dynamic mathematical model, by means of a suitable time discretization, has been changed into a “static” one, in order to use static network flow algorithms while taking into account the “unsteady” nature of the air traffic congestion problems. The complexity of the model requires some preliminary effort, such as the identification of some characteristic parameters of the system. In this paper, the network theory is applied to evaluate the influence of the time discretization interval on the model significancy with respect to the actual traffic situation. In particular, a computational example concerning the Rome air traffic control region is presented and the relative results are discussed.

Children as pedestrians: Abilities and limitations†

The purpose of this paper is to present information on the feasibility of educational objectives in the field of traffic education for young children. In order to do so. it is necessary to answer four questions. These are: (1) Which behavior is desired? (2) Which functions and abilities are required for a safe performance of the tasks described in question 1? On the basis of existing literature a large number of necessary functions and abilities could be distinguished. These were combined into four groups related to: the perception of oncoming traffic, judgments to be made, the decision-making process and some additional tasks. (3) How do the necessary functions and abilities develop and at what age can they be used adequately? A survey of the traffic safety literature as well as the general child development literature forms the main part of this paper. (4) What implications does this development have for the leaching objectives? The results of the literature survey show, that a great lack of relevant research does exist. The relation of most studies with the actual traffic task is often a very weak one, even within the traffic safety literature. Only a few studies have been carried out in actual traffic situations and even in these studies the relation with crossing behavior has not been studied. Hence, it is not possible at present to give a detailed set of objectives feasible at a certain age. Although some objectives can be defined, much more research is necessary before final conclusions can be reached.