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Free Flow Capacity and Queue Discharge Rate: Long-Term Changes

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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Car-Following Described by Blending Data-Driven and Analytical Models: A Gaussian Process Regression Approach

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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Ramp Metering with Microscopic Gap Detection Algorithm Design and Empirical Acceleration Verification

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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Influencing the queue configuration to increase bicycle jam density and discharge rate: An experimental study on a single path

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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Estimation of the Change in Cumulative Flow over Probe Trajectories using Detector Data

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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A Macroscopic Flow Model for Mixed Bicycle–Car Traffic

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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The Influence of Jam Density and Merging Cyclists on the Queue Discharge Rate

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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On the value of relative flow data

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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Mainstream traffic flow control at sags

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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Capacity, Capacity Drop and Relation of Capacity to the Path Width in Bicycle Traffic

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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Large-Scale Bicycle Flow Experiment: Setup and Implementation

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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Using advanced adaptive cruise control systems to reduce congestion at sags: An evaluation based on microscopic traffic simulation

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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Multi-class traffic flow on a partially space-shared road

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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Multiobjective Calibration Framework for Pedestrian Simulation Models: A study on the Effect of Movement Base Cases, Metrics, and Density Levels

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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Macroscopic traffic state estimation using relative flows from stationary and moving observers

van Erp, P.B.C. (author), Knoop, V.L. (author), Hoogendoorn, S.P. (author)

This article presents a procedure to estimate the macroscopic traffic state in a pre-defined space-time mesh using relative flow data collected by stationary and moving observers. The procedure consist of two consecutive and independent processes: (1) estimate point observations of the cumulative vehicle number in space-time, i.e., N(x, t),...

journal article 2018

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Real-time schattingen van voertuigaccumulatie met FCD

van Erp, P.B.C. (author), Knoop, V.L. (author), Hoogendoorn, S.P. (author)

In ruwe vorm zijn floating car data rijk en uiterst gedetailleerd. Het punt is alleen dat we om privacyredenen niet met die ruwe data mogen werken – we moeten het doen met geaggregeerde data die door een privacyfilter zijn gehaald. Is daarmee nog enige verkeersmanagement-eer te behalen? Jawel, mits je de FCD slim combineert met bijvoorbeeld...

journal article 2018

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Rijstrookwisselgedrag scherper in beeld: Een rij-experiment en online enquête

de Baat, Marco (author), Knoop, V.L. (author), Hoogendoorn, S.P. (author)

journal article 2018

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A geometric Brownian motion car-following model: towards a better understanding of capacity drop

Yuan, K. (author), Lavala, Jorge (author), Knoop, V.L. (author), Jiang, Rui (author), Hoogendoorn, S.P. (author)

Traffic flow downstream of the congestion is generally lower than the pre-queue capacity. This phenomenon is called the capacity drop. Recent empirical observations show a positive relationship between the speed in congestion and the queue discharge rate. Literature indicates that variations in driver behaviors can account for the capacity drop....

journal article 2018

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Lane Change Behavior on Freeways: An Online Survey Using Video Clips

Knoop, V.L. (author), Keyvan-Ekbatani, M. (author), de Baat, Marco (author), Taale, Henk (author), Hoogendoorn, S.P. (author)

Freeways forman important part of the road network. Yet, driving behavior on freeways, in particular lane changes and the relation with the choice of speed, is not well understood. To overcome this, an online survey has been carried out. Drivers were shown video clips, and after each clip they had to indicate what they would do after the moment...

journal article 2018

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Macroscopic Traffic State Estimation: Understanding Traffic Sensing Data-Based Estimation Errors

van Erp, P.B.C. (author), Knoop, V.L. (author), Hoogendoorn, S.P. (author)

Traffic state estimation is a crucial element in traffic management systems and in providing traffic information to road users. In this article, we evaluate traffic sensing data-based estimation error characteristics in macroscopic traffic state estimation. We consider two types of sensing data, that is, loop-detector data and probe speed...

journal article 2017