Elżbieta Macioszek

Methods of Modeling the Bicycle Traffic Flows on the Roundabouts

The paper deals with the bicycle traffic issues on the roundabouts and their nearby areas. The fundamental elements of traffic management and infrastructure used in traffic regulation on the roundabouts have been presented. The authors present also the examples of typical settings of the bicycle paths. Amongst the conventional solutions some interesting ones from abroad, from the Netherlands in particular, which grant a huge level of traffic safety while crossing a roundabout, have also been introduced.

Problems and Issues with Running the Cycle Traffic through the Roundabouts

The paper deals with the bicycle traffic issues on the roundabouts and their nearby areas. The bicycle traffic characteristics as well as pros and cons of a bicycle as a means of transportation with the current situation of cycling in Poland have been presented. The authors also presents the results of research on traffic safety of the cyclists on the traffic circles. In addition, the fields of knowledge lacking complete information on the solutions to bicycle traffic on the roundabouts are being pointed out.

Analysis of the Effect of Congestion in the Lanes at the Inlet to the Two-Lane Roundabout on Traffic Capacity of the Inlet

A considerable number of two-lane roundabouts is used in Poland today. Observations of the behaviour of drivers who drive through this type of intersections show that the lanes in the area of the intersection are not equally loaded. Drivers are more willing to use the right traffic lane at the roundabout’s inlet, even if traffic intensity is considerably high. With regard to this fact, the paper presents the analysis of the effect of load in the individual lanes at the inlet of a two-lane roundabout on traffic capacity at the inlet. Analysis focused on conventional two-lane roundabouts, without consideration of the cases of traffic organization typical of turbo roundabouts with two lanes at the inlet.

Geometrical Determinants of Car Equivalents for Heavy Vehicles Crossing Circular Intersections

Individual groups of vehicles affect the conditions of traffic streams to different extent. For a given group of vehicles, this effect should be approached as a variable determined by some geometrical and traffic properties. This impact can be estimated by using one of the models used for the purpose. One of such models is a model based on comparisons speed of group of vehicles in traffic stream. This paper presents the results of the measurements of the spatial average velocity of vehicles that cross circular intersections (usually roundabouts) and the analyses of the effect of selected geometrical parameters on the velocity of vehicles crossing an intersection and consequently the car equivalents for heavy vehicles.

Relationship between Vehicle Stream in the Circular Roadway of a One-Lane Roundabout and Traffic Volume on the Roundabout at Peak Hour

One-lane roundabouts are popular mainly due to high traffic capacity and the opportunities for ensuring a high level of road traffic safety to the users. Furthermore, they have been very often used as an effective means of reducing the traffic. This paper presents the analysis of relationships of a one-lane roundabout on the main factors that determine its value, such as total traffic volume that unloads the intersection at a particular external diameter of the roundabout. The effect of the study is development of a nomogram of traffic capacity for one-lane roundabouts.

The Influence of Motorcycling and Cycling on Small One-Lane Roundabouts Capacity

The number of travels by a bicycle as a means of transportation in Poland in recent years, in spite of lack of a complex network of the bicycle tracks, has been systematically increasing. The growth of the number of people using a bicycle as a means of transportation is not accompanied by the growth of a proper infrastructure for cyclists or by any promotion campaigns. There is a lack of appropriate number of separate bicycle paths, bicycle lanes, so bicyclists, motorcyclists and vehicles form mixed traffic flows. The problem of the influence of motorcyclists and cyclists in mixed traffic flows on small one-lane roundabouts capacity has been presented in this article. The results of analysis have shown that motorcyclists and cyclists trajectories on small one-lane roundabouts have strongly influenced other traffic participants’ behaviour.

The road safety at turbo roundabouts in Poland

There are to two groups of turbo roundabouts used currently in Poland. The first group is turbo roundabouts with geometry and traffic organization designed following the model of Dutch turbo roundabouts with raised lane dividers. The other group is turbo roundabouts with traffic organization which entirely or partly corresponds to traffic organization of conventional turbo roundabouts, but with lane dividers not present, with their function performed by a single continuous line of P-2 type. Turbo roundabouts in the world are considered as solutions which are characterized by a high level of road safety and allow for effective flow at substantial traffic intensities. The data about turbo roundabouts in Poland analysed by the author show that there are substantially more turbo roundabouts without raised lane dividers. The paper attempts to answer to the question of whether turbo roundabouts with lane dividers in the form of a single continuous line ensure the appropriate level of road safety. Furthermore, the comparison of the level of road safety in turbo roundabouts equipped in raised lane dividers with turbo roundabouts with lane separators in the form of continuous line revealed that turbo roundabouts with raised lane dividers are safer solutions than turbo roundabouts with traffic lane dividers in the form of continuous line.

Analysis of Significance of Differences Between Psychotechnical Parameters for Drivers at the Entries to One-Lane and Turbo Roundabouts in Poland

The psychotechnical parameters of drivers of vehicles at the entries to intersections without traffic lights and roundabouts include critical headway and follow-up headway. The paper presents analysis of significance of differences in values of these parameters for drivers of vehicles at the entries to one-lane roundabouts and turbo roundabouts. The comparative analysis was used to evaluate entries of one lane and turbo roundabouts with traffic organization with a single traffic lane with possibility of entering a single lane on the main circular roadway. The results obtained in the study will help find differences in the parameters compared.

First and Last Mile Delivery – Problems and Issues

“First and Last Mile Delivery” stands for freight transport logistics over the first and the last part of the way to the customer, accordingly. In freight transport, the first and the last mile are most cost intensive. In the last phase of transport, it is difficult to gather and put shipments together, which results in the costs in that area usually being disproportionately high. The problems of last mile delivery usually stem from the fact that deliveries are composed of individual orders and from a significant level of dispersal of destinations, as each order must be delivered to a different address. Similar problems are related to first mile freight transport. This article addresses the problems and issues connected with first and last mile delivery.

The Comparison of Models for Follow-up Headway at Roundabouts

One of the basic parameter used for roundabout entry capacity calculation is follow-up headway. This parameter beyond critical headway and traffic volume on roundabout roadway major for vehicle drivers from entry determines roundabout entry capacity. The comparative analysis of models and studies on follow-up headway estimation have been presented in this article. The analysis were made for single lane, two lane and turbo roundabouts. The largest number of models and studies of follow-up headway parameter refers to single lane roundabouts. The least studies were devoted to values of follow-up headway parameter at turbo roundabouts due to the fact that this is still relatively a new type of roundabout in compare with single lane or two lane roundabouts.