Renata Żochowska

ITS Services Packages as a Tool for Managing Traffic Congestion in Cities

Traffic congestion understood as transportation crowding is an important factor for increasing inconvenience of life and passing through element of transportation infrastructure in urban areas. Measures aimed at mitigating the negative effects of such situations should be taken at different levels of traffic management: strategic, tactical and operational. This requires a close cooperation and coordination between planners, designers and traffic engineers. The article presents strategies for managing congestion in cities using packages of ITS services. It also presents the concept of an integrated approach to this issue in the context of the theory of traffic flow.

Modelling of expected traffic smoothness in urban transportation systems for ITS solutions

In urban networks, with dense traffic flows and a high risk of the disruption (even in the form of a short queue of vehicles) the probability of occurrence of such a situation (disruption and queue) is a better measure of the probabilistic description of the capacity constraints than the expected waiting time in the queue, because the probability takes into account the risk of delay in the traffic flow from the point of view of the person that plans a trip. The functions of expected smoothness of the traffic flows in the elementary nodes and the expected waiting time in the queue for different packages of ITS services have been presented in the mathematical forms.

Selected Issues of a Coordinated Adaptive Road Traffic System Application within the Silesian Conurbation

The article deals with the selected issues of deployment of a coordinated adaptive road traffic control system within the Silesian conurbation. One needs to identify all peculiar problems allocated with this region. This will include the range, structural and administration issues. All of them are associated with the distributed traffic management realized by different local authorities. Since deployment of such complex system relies mainly on the ITS solutions, all important technical issues applying to the conurbation are being presented. The authors have specifically highlighted a problem of collecting information on travel destinations. The efficient systems in use base on the dynamic methods and need the Origin-Destination matrices to be updated due to a current situation on roads. All the conventional methods of estimating such matrices do not apply and one needs to consider the assumptions on and limitations of the input data and complexity of computing.

Results of Research of the Traffic Safety at Signalized Intersection with Countdown Timers

The article is a continuation of the research work carried out by the authors on determining the impact of the countdown timers on traffic conditions, and—in this case—on traffic safety at the intersections. The paper presents the results of research for assessing the impact of the role of the intersection with the countdown timers in transportation network of the city on the safety of the intersections. Moreover, the article also demonstrates the force of the influence of the countdown timers on the level of traffic safety, depending on the function of the intersection in transportation network. For scientific purposes, the traffic measurements were conducted which have been described in detail in another article [1].

Work Zones and Temporary Traffic Organization at Roundabout - Review of Selected Solutions

In many countries roundabouts are becoming an increasingly common element of transportation infrastructure. Therefore, like other elements of the infrastructure, they may be subject to periodic closures associated with i.e. modernization of infrastructure, maintenance of road signs and traffic safety devices or renovation of road surface. Such closures require implementation of temporary traffic organization. Due to unique features of roundabouts it appears that specific methods of organizing work zones at such objects should be developed. This paper contains a proposal of typology of temporary traffic organization at roundabouts and a review of possible solutions for each group.

Selected Aspects of the Methodology for Delimitation of the Area of Urban Agglomeration in Transportation Models for the Evaluation of ITS Projects

The article presents the selected issues and the algorithm of methodology for delimitation of the urban area for the needs of construction of four-step transportation model. In the methodology the use of the transportation model for the evaluation of ITS projects has been taken into account. The essence of the presented methodology is to take into account three types of criteria for delimiting the area and different levels of reference. Presented issues became the basis for the development of mathematical formalization of delimitation problem. The examples relate in particular to urban agglomeration with the nature of a conurbation - Upper Silesian Agglomeration in Poland.

Selected Aspects of the Methodology of Traffic Flows Surveys and Measurements on an Urban Agglomeration Scale with Regard to ITS Projects

The article presents the scope and the algorithm of traffic flows surveys and measurements (TFSM) necessary for the construction of an urban agglomeration transportation model (UATM) for ITS projects. The basic guidelines for determining the locations of the measurement points have also been discussed. To show the structure of TFSM the algorithm of action during Comprehensive Traffic and Transportation Studies for Transportation Modeling with Evaluation of ITS Project, has been presented. The examples relate in particular to urban agglomeration with the nature of a conurbation - Upper Silesian Agglomeration in Poland.