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Knoop, V.L. (author), Hoogendoorn, S.P. (author)
When do traffic jams emerge? Can we predict, given certain demand levels, when queuing will occur, how long the queues will be, how they will propagate in space and time, and how long it takes for the congestion to resolve? Why does an overloaded traffic network underperform? This chapter gives a basic introduction in traffic flow theory which...
book chapter 2023
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Knoop, V.L. (author), Hoogendoorn, S.P. (author)
Traffic jams are caused by a traffic demand that exceeds road capacity. Road capacity, therefore, is an important road feature. This capacity might change as function of time, even for the same road stretch, owing to changing driving behaviors or vehicle characteristics. In this study, we empirically analyzed the changes in road capacity over a...
journal article 2022
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Soldevila, Ignasi Echaniz (author), Knoop, V.L. (author), Hoogendoorn, S.P. (author)
Traffic engineers rely on microscopic traffic models to design, plan, and operate a wide range of traffic applications. Recently, large data sets, yet incomplete and from small space regions, are becoming available thanks to technology improvements and governmental efforts. With this study we aim to gain new empirical insights into longitudinal...
journal article 2021
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Klomp, Stefan R. (author), Knoop, V.L. (author), Taale, Henk (author), Hoogendoorn, S.P. (author)
Freeway on-ramp areas are susceptible to traffic congestion during peak hours. To delay or prevent the onset of congestion, ramp metering can be applied. A Ramp Metering Installation (RMI) controls the inflow from the on-ramp to the main line so that the total flow can be kept just below capacity. Current ramp metering algorithms apply...
journal article 2021
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Knoop, V.L. (author), Vuik, Cornelis (author), Duives, D.C. (author), Hoogendoorn, S.P. (author)
Editorial
contribution to periodical 2021
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Wierbos, M.J. (author), Knoop, V.L. (author), Bertini, R.L. (author), Hoogendoorn, S.P. (author)
Congestion in bicycle traffic is a daily occurrence at many urban intersections. It is known that a higher density in the queue leads to a higher discharge rate. In theory, higher jam densities than those currently observed in practice are feasible. This leads to our hypothesis that the delay at intersections can be further reduced when cyclists...
journal article 2021
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Wierbos, M.J. (author), Knoop, V.L. (author), Goni Ros, B. (author), Hoogendoorn, S.P. (author)
An increasing number of people use the bicycle for urban trips resulting in local congestion at intersections, especially during peak hours. Understanding the queue dynamics is key to find the correct measures that can reduce the delays for cyclists without affecting other traffic modes. To this end, the discharge process of bicycle queues is...
journal article 2020
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van Erp, P.B.C. (author), Knoop, V.L. (author), Smits, Erik Sander (author), Tampère, Chris (author), Hoogendoorn, S.P. (author)
Detector data can be used to construct cumulative flow curves, which in turn can be used to estimate the traffic state. However, this approach is subject to the cumulative error problem. Multiple studies propose to mitigate the cumulative error problem using probe trajectory data. These studies often assume “no overtaking” and thus that the...
journal article 2020
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Wierbos, M.J. (author), Knoop, V.L. (author), Hanseler, F.S. (author), Hoogendoorn, S.P. (author)
Bicycles are gaining popularity as a mode of transport resulting in a mixed bicycle–car traffic situation on urban roads. Cyclists however, are hardly included in traffic flow models which complicates the design of safe and congestion-free traffic situations. This work introduces class-specific speed functions based on two variables, being space...
journal article 2020
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van Erp, P.B.C. (author), Knoop, V.L. (author), Hoogendoorn, S.P. (author)
Traffic flow can be described using three dimensions, i.e., space x, time t and cumulative flow N. This study considers estimating the cumulative flow over space and time, i.e., N(x,t), using relative flow data collected by stationary and moving observers. Stationary observers, e.g., loop-detectors, can observe flow at fixed position over...
journal article 2020
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Knoop, V.L. (author), Hanseler, F.S. (author), Wierbos, M.J. (author), Gavriilidou, A. (author), Daamen, W. (author), Hoogendoorn, S.P. (author)
Density is one of the most relevant variables in a traffic flow description. For objects in 2 dimensions, density can be determined by the space that is allocated to each of the objects. This paper introduces a new way of computing the space available for a bicyclist, accounting for speed and accounting for the non-zero size of a bicycle. This...
conference paper 2020
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Yuan, K. (author), Knoop, V.L. (author), Hoogendoorn, S.P. (author)
Scarce urban space makes urban streets have to be partly shared by cars and cyclists. Traffic flow can be considerably influenced by cyclists, which are comparatively slower than cars. The fundamental diagram (FD) can change greatly, correlating to bike lane length and the cyclist flow. Models for the traffic dynamics on the space-shared streets...
journal article 2019
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Sparnaaij, M. (author), Duives, D.C. (author), Knoop, V.L. (author), Hoogendoorn, S.P. (author)
Ideally, a multitude of steps has to be taken before a commercial implementation of a pedestrian model is used in practice. Calibration, the main goal of which is to increase the accuracy of the predictions by determining the set of values for the model parameters that allows for the best replication of reality, has an important role in this...
journal article 2019
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Goni Ros, B. (author), Knoop, V.L. (author), van Arem, B. (author), Hoogendoorn, S.P. (author)
Sags are freeway sections along which the gradient changes significantly from downward to upward. The capacity of sags is considerably lower than the capacity of normal sections. Consequently, sags are often freeway bottlenecks. Recently, several control measures have been proposed to improve traffic flow efficiency at sags. Those measures...
journal article 2019
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Knoop, V.L. (author), Taale, Henk (author), Meulenberg, Michel (author), van Erp, P.B.C. (author), Hoogendoorn, S.P. (author)
Demand exceeding the capacity of a bottleneck will create congestion upstream of that bottleneck. Once this congestion occurs, the maximum flow through this bottleneck decreases (capacity drop). By limiting the flow towards the bottleneck, one can prevent or postpone the capacity drop and the accompanying congestion. In case the bottleneck is...
conference paper 2019
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Wierbos, M.J. (author), Knoop, V.L. (author), Hanseler, F.S. (author), Hoogendoorn, S.P. (author)
Bicycle usage is encouraged in many cities because of its health and environmental benefits. As a result, bicycle traffic increases which leads to questions on the requirements of bicycle infrastructure. Design guidelines are available but the scientific substantiation is limited. This research contributes to understanding bicycle traffic flow...
journal article 2019
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Gavriilidou, A. (author), Wierbos, M.J. (author), Daamen, W. (author), Yuan, Y. (author), Knoop, V.L. (author), Hoogendoorn, S.P. (author)
Cycling research at the operational behavioral level is limited, mainly because of the lack of empirical data. To overcome this data shortage, we performed a controlled, large-scale cycling experiment in the Netherlands. In this paper we describe the methodology for setting up and implementing such an experiment, from the motivation of its...
journal article 2019
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Goni Ros, B. (author), Schakel, W.J. (author), Papacharalampous, Alexandros E. (author), Wang, M. (author), Knoop, V.L. (author), Sakata, Ichiro (author), van Arem, B. (author), Hoogendoorn, S.P. (author)
Sags are roadway sections along which the gradient increases gradually in the direction of traffic. Sags are generally bottlenecks in freeway networks. Previous research suggests that traffic management measures using advanced Adaptive Cruise Control (ACC) systems could reduce congestion on freeways, but little is known about their potential...
journal article 2019
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Knoop, V.L. (author), van Erp, P.B.C. (author), Leclercq, Ludovic (author), Hoogendoorn, S.P. (author)
<br/>The Macroscopic Fundamental Diagram (MFD) describes the relation between accumulation and speed in a zone. While theoretically expected, empirical validations have been done with limited numbers of floating car (e.g., taxi) data, and loop detectors. This paper will verify existence, shape and crispness of the MFD using Floating Car Data ...
conference paper 2019
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Daamen, W. (author), van den Heuvel, Jeroen P.A. (author), Knoop, V.L. (author), Hoogendoorn, S.P. (author)
The macroscopic fundamental diagram (MFD) relates the flow, density and speed of an entire network. So far, the MFD has been mostly applied to cases where pedestrians and vehicles were aiming to reach their destinations as fast as possible. However, pedestrian facilities involve different behaviours. Especially in train stations, travellers...
conference paper 2019
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