Report

Recently it has been proposed that the performance of a complete network can be represented graphically using only aggregated data for flow and density. The resulting graph is the macroscopic fundamental diagram (MFD), which relates the average flow and the average density (network density) of a network to each other. The resulting shape is often concave, meaning that the network output could be maximised if a fixed number of vehicles can be maintained in a network. In order to gain a deeper insight into what factors affect the shape of the MFD, how the MFD is related to the structure… Read More »The Effect of Network Structure and Signal Settings on the MFD

Rush-hour lanes and pluslanes have been operational in the Netherlands since 1996. They are intended to increase capacity without the need to add an extra lane to the cross-section. Individually, rush-hour lanes and pluslanes have been evaluated. However, not much research compares designs for rush-hour lane and pluslane with each other. In this research, long-term data will be used to get detailed information about the performance of different rush-hour lane and pluslane designs. Also, a driving simulator study is performed to gain insight in the underlying behavioral factors and to analyze the performance of changes in rush-hour lane designs. The… Read More »Performance of Rush-hour and Plus Lanes – A study to behavioral and design factors

To improve traffic conditions and safety, a large number of traffic management applications are being used in daily practice. These traffic management applications need information on the prevailing traffic conditions to adequately function. To obtain these, traffic sensors are used. Traffic can be monitored through a large range of different traffic detectors. These detectors are often quite inaccurate and costly. In the Netherlands, induction loops are the most widely used traffic sensors. The Smart In-Car project offers the possibility to investigate a new type of traffic monitoring. In this project, the values from several in-vehicle sensors, obtained from the CAN… Read More »Level of Service estimation with in-vehicle sensor floating car data

Traffic flow modelling has developed rapidly over the last two decades. In many applications, the models are combined with measured data concerning the current traffic state and with fast computational methods. Because of this combination it has become possible to make accurate and useful short term predictions about the evolution of the traffic state. The predictions can be used to inform and advise road users, for example about alternative routes. Furthermore, the predictions can be used to control traffic in an efficient way in order to prevent or reduce delays. The predictions are in particular useful in the case of… Read More »Multi-class continuum traffic flow models

The road network in the Netherlands can be considered as saturated with considerable levels of congestion. Not so long ago, mobility policies focused mainly on reducing travel times. But we have recently come to realise that travelling time reliability is at least as important to travellers, hauliers and shippers. The importance of travelling time reliability for passenger and goods traffic has been acknowledged by government and local authorities. A possible answer to the problems presented itself in the U.S. due to circumstances with regard to the poor performance displayed by the previously developed dedicated carpool lanes. By allowing also the… Read More »HOT lanes – Implementation considerations and assessment

Microscopic traffic simulation models are a widely used tools for transport system analysis and management. These tools are used to model the complexity of the systems and to evaluate various traffic management alternatives in order to determine the optimal solution for any traffic scenario. A classical way to represent vehicle interactions at merges at the microscopic scale is to combine a gap-acceptance model with a car-following algorithm. With the gap acceptance the choice for a certain gap is modelled. Recently a new concept framework for modelling merging behaviour was proposed. This concept is based on gap selection. The choice decision… Read More »Modelling merging behaviour on freeway on-ramps

In this thesis the use of in-vehicle data, obtained from a uCAN, for the estimation of the traffic speed is investigated. Since vehicles are not equipped with a uCAN yet, the uCAN data is emulated. For this emulation, the traffic simulation model Fosim is used. With the emulated uCAN data, the minimum percentage of vehicles equipped with a uCAN that is necessary to accurately estimate the traffic speed is determined. This minimum percentage is equal to the minimum percentage for which the corresponding estimator for the traffic speed satisfies the accuracy requirement of NDW. The obtained percentage is applied to… Read More »Percentage of uCAN equipped vehicles needed to estimate traffic speed accurately

Increased mobility has caused a constant increase in the amount of traffic since the introduction of the first cars in the 19th century. This increase caused several negative effects, such as congestion or emissions of air pollutants and greenhouse gasses. One way of reducing these negative effects is making more efficient use of the existing infrastructure. Intelligent Transport Systems (ITS) are a means to do this. Integrated use of different kinds of ITS could increase the effectiveness of all components of the integrated system. In 15 years all road-users are expected to be connected through the use of smart phones… Read More »Design of an urban traffic controller that incorporates route advice given by in-vehicle navigation systems

Traffic congestion continues to remain a serious problem in most countries, with significant economic and environmental losses. ‘Intelligent Transport Systems (ITS)’ that utilize advanced information and communication technology for managing road infrastructure, including vehicles and users, have shown great potential in dealing with this problem. However, most current traffic management measures, like route guidance, ramp metering and variable speed limits are designed and implemented independently. Potentially counter-productive when deployed simultaneously, integration of these measures can benefit from synergic effects. The aim of this work is to integrate a near-future variable speed control strategy with ramp metering, to operate efficiently at… Read More »Integrated approach to variable speed limits and ramp metering

The traffic state of a road network can be described by a so called macroscopic fundamental diagram (MFD). In this diagram the average production is related to the accumulation of traffic in a specific road network. A promising application field of the MFD is to introduce the MFD in the algorithm of a traffic controller. Due to increasing congestion on urban roads, extra road capacity might be needed. However, for economic reasons better usage of the current road capacity is preferred. Therewith, the intersection density in road networks has increased nowadays. One of the consequences is that the way of… Read More »Design of a subnetwork controller based on MFD’s and perimeter flows