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Li, G. (author), Knoop, V.L. (author), van Lint, J.W.C. (author)Traffic condition forecasting is fundamental for Intelligent Transportation Systems. Besides accuracy, many services require an estimate of uncertainty for each prediction. Uncertainty quantification must consider the inherent randomness in traffic dynamics, the so-called aleatoric uncertainty, and the additional distrust caused by data shortage...journal article 2024
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Knoop, Max W. (author), Hartog, F.H. (author), Schrijer, F.F.J. (author), van Campenhout, O.W.G. (author), van Nesselrooij, M. (author), van Oudheusden, B.W. (author)We present an experimental realisation of spatial spanwise forcing in a turbulent boundary layer flow, aimed at reducing the frictional drag. The forcing is achieved by a series of spanwise running belts, running in alternating spanwise direction, thereby generating a steady spatial square-wave forcing. Stereoscopic particle image velocimetry...journal article 2024
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Li, G. (author), Li, Zirui (author), Knoop, V.L. (author), van Lint, J.W.C. (author)Predicting the trajectories of road agents is fundamental for self-driving cars. Trajectory prediction contains many sources of uncertainty in data and modelling. A thorough understanding of this uncertainty is crucial in a safety-critical task like auto-piloting a vehicle. In practice, it is necessary to distinguish between the uncertainty...journal article 2024
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Li, G. (author), Li, Zirui (author), Knoop, V.L. (author), van Lint, J.W.C. (author)Resolving predicted conflicts is vital for safe and efficient autonomous vehicles (AV). In practice, vehicular motion prediction faces inherent uncertainty due to heterogeneous driving behaviours and environments. This spatial uncertainty increases non-linearly with prediction time horizons, leading AVs to perceive more road space occupied by...journal article 2024
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Chen, K. (author), Li, Zhibin (author), Liu, Pan (author), Knoop, V.L. (author), Han, Yu (author), Jiao, Y. (author)A lane-changing (LC) maneuver may cause the follower in the target lane (new follower) to decelerate and give up space, potentially affecting crash risk and traffic flow efficiency. In congested flow, a more aggressive LC maneuver occurs where the lane changer is partially next to the new follower and creates negative gaps, namely negative...journal article 2024
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Ni, Y. (author), Knoop, V.L. (author), Kooij, J.F.P. (author), van Arem, B. (author)A substantial number of vehicles nowadays are equipped with adaptive cruise control (ACC), which adjusts the vehicle speed automatically. However, experiments have found that commercial ACC systems which only detect the direct leader amplify the propagating disturbances in the platoon. This can cause severe traffic congestion when the number...journal article 2024
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Zhao, Jing (author), Knoop, V.L. (author), Sun, Jian (author), Ma, Zian (author), Wang, M. (author)Path dispersion (the spatial distribution of vehicular paths) is an important feature of traffic flow inside intersections and differs from traffic flow running along traffic lanes at road segment, especially under conflicting movements. The path dispersion reflects the operational features of traffic flow and is related to driving behaviour,...journal article 2023
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Zhao, J. (author), Knoop, V.L. (author), Wang, M. (author)Microscopic traffic flow models enable predictions of traffic operations, which allows traffic engineers to assess the efficiency and safety effects of roadway designs. Modeling vehicle trajectories inside intersections is challenging because there is an infinite number of possible paths in a two-dimensional space, and drivers can...journal article 2023
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Chen, Kequan (author), Knoop, V.L. (author), Liu, Pan (author), Li, Zhibin (author), Wang, Yuxuan (author)Lane-changing (LC) in congested traffic has been identified as a trigger for the sudden deceleration behavior of the new follower in the target lane, leading to severe traffic disturbances. Thus, investigating the response of the new follower to an LC maneuver is an important research topic in the literature. To date, numerous efforts have...journal article 2023
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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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Shiomi, Y. (author), Li, G. (author), Knoop, V.L. (author)Traffic dynamics on freeways are stochastic in nature because of errors in perception and operation of drivers as well as the heterogeneity between and within drivers. This stochasticity is often represented in car-following models by a stochastic term, which is assumed to follow a normal distribution for the convenience of mathematical...journal article 2023
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Li, G. (author), Jiao, Y. (author), Knoop, V.L. (author), Calvert, S.C. (author), van Lint, J.W.C. (author)Car-Following (CF), as a fundamental driving behaviour, has significant influences on the safety and efficiency of traffic flow. Investigating how human drivers react differently when following autonomous vs. human-driven vehicles (HV) is thus critical for mixed traffic flow. Research in this field can be expedited with trajectory datasets...conference paper 2023
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Aarts, Michiel J.M. (author), Ellerbroek, Joost (author), Knoop, V.L. (author)The traffic density of small aerial vehicles operating within urban environments is expected to increase significantly in the near future. This urban environment is highly constrained due to being limited to the low-altitude airspace directly above the existing road network. Multiple studies have addressed factors influencing the capacity of...journal article 2023
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Yuan, K. (author), Knoop, V.L. (author)The macroscopic fundamental diagram (MFD) is developed to describe traffic operations aggregated over an area. The MFD is defined by network traffic states as a relationship between the accumulation of vehicles and flow or speed of vehicles. The concept of the MFD has been applied to model traffic dynamics and to design control strategies....journal article 2023
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Dias Neto, J. (author), Nuijens, Louise (author), Unal, C.M.H. (author), Knoop, S.A.G. (author)This paper introduces an experimental setup for retrieving horizontal wind speed and direction profiles with a high temporal and vertical resolution for process studies and validation of convection-permitting model simulations. The CMTRACE (tracing convective momentum transport in complex cloudy atmospheres) campaign used collocated wind lidar...journal article 2023
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Chen, Kequan (author), Knoop, V.L. (author), Liu, Pan (author), Li, Zhibin (author), Wang, Yuxuan (author)The pre-insertion process called anticipation is an essential component of a lane-changing manoeuvre. There is little empirical research regarding the impact of anticipation. Thus, this paper aims to explore the behaviour of the new follower (NF) in the target lane when it encounters anticipation by using new trajectory datasets. The changing...journal article 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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- Zhong, Renxin (author), He, Zhengbing (author), Chow, Andy H.F. (author), Knoop, V.L. (author) contribution to periodical 2022
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Dias Neto, J. (author), Nuijens, Louise (author), Unal, C.M.H. (author), Knoop, Steven (author)Convective clouds may be associated with substantial transport of momentum. Much of what we know about convective momentum transport stems from high-resolution simulations because high-resolution measurements of the wind profile are rare. This study exploits ground-based remote sensing techniques to visualize wind below and within clouds and...poster 2022
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Li, G. (author), Knoop, V.L. (author), van Lint, J.W.C. (author)Accurate short-term traffic forecasting is the cornerstone for Intelligent Transportation Systems. In the past several decades, many models have been proposed to continuously improve the predictive accuracy. A key but unsolved question is whether there is a theoretical bound to the accuracy with which traffic can be predicted and whether that...journal article 2022