working paper
Vehicle re-identification using heterogeneous detection systems
Publication Date
August 1, 2003
Author(s)
Working Paper
UCI-ITS-TS-WP-03-9
Area of Expertise: Unspecified
conference paper
A Generalized Diffusion Model for Preference and Response Time: Application to Ordering Mobility-on- Demand Services
100th Transportation Research Board (TRB) Annual Meeting
Publication Date
January 1, 2021
Author(s)
Suggested Citation
Jiangbo Yu and Michael F. Hyland (2021) “A Generalized Diffusion Model for Preference and Response Time: Application to Ordering Mobility-on- Demand Services”. 100th Transportation Research Board (TRB) Annual Meeting, Washington, DC. conference paper
Anticipatory Fleet Operation for Shared-use Autonomous Mobility Services with Learning-based Vehicle Repositioning
102nd Annual Meeting of the Transportation Research Board
Publication Date
January 1, 2023
Author(s)
Monika Filipovska, Michael Hyland
Suggested Citation
Monika Filipovska and Michael F. Hyland (2023) “Anticipatory Fleet Operation for Shared-use Autonomous Mobility Services with Learning-based Vehicle Repositioning”. 102nd Annual Meeting of the Transportation Research Board. conference paper
Exploring scenarios for the introduction of freight trams in Barcelona
Proceedings of 91st annual meeting of the transportation research board, washington, DC
Publication Date
January 1, 2012
Author(s)
Robert Regue, A.L. Bristow
Suggested Citation
R. Regué and A.L. Bristow (2012) “Exploring scenarios for the introduction of freight trams in Barcelona”, in Proceedings of 91st annual meeting of the transportation research board, washington, DC. research report
Detecting changes in accident rates using a hierarchical Bayesian approach: An application to the I-710 and the implementation of the PierPASS program
Publication Date
January 1, 2017
Author(s)
Suggested Citation
Ankoor Bhagat, Jean-Daniel Saphores and R Jayakrishnan (2017) Detecting changes in accident rates using a hierarchical Bayesian approach: An application to the I-710 and the implementation of the PierPASS program. conference paper
Prediction of short-term freeway traffic volume using recursive least squares and lattice filtering
Applications of advanced technologies in transportation
Publication Date
January 1, 1998
Author(s)
SM Kang, Stephen Ritchie, R. (Jay) Jayakrishnan
Abstract
Estimating and predicting the dynamic variation of traffic variables such as volume and speed is becoming increasingly important for intelligent transportation systems applications. In this paper, we present a linear model for the short-term (30 second) prediction of freeway traffic volumes using a recursive least squares algorithm with a lattice filter. An innovative feature of the model is that all of the parameters, such as the optimal weights and the model order, are time-varying and are automatically updated in real-time so that unexpected traffic variations can be addressed by varying the parameters. Recursive filtering algorithms are applied in order to save computation time and storage space. The results of the performance analysis show that the proposed model works well under different conditions, including multiple locations and recurrent and non-recurrent congestion.
Suggested Citation
SM Kang, SG Ritchie and R Jayakrishnan (1998) “Prediction of short-term freeway traffic volume using recursive least squares and lattice filtering”, in . Hendrickson, CT and Ritchie, SG (ed.) Applications of advanced technologies in transportation. AMER SOC CIVIL ENGINEERS, pp. 255–264. conference paper
Towards Adaptive Incident Detection Algorithms
6th ITS World Congress
Publication Date
November 1, 1999
Author(s)
Suggested Citation
Baher Abdulhai and Stephen G. Ritchie (1999) “Towards Adaptive Incident Detection Algorithms”. 6th ITS World Congress, Toronto. Available at: https://www.researchgate.net/publication/228968845_'Towards_adaptive_incident_detection_algorithms. conference paper
CrowdWiFi. efficient crowdsensing of roadside WiFi networks
Proceedings of the 15th international middleware conference on - middleware '14
Publication Date
January 1, 2014
Author(s)
Abstract
In this paper, we present CrowdWiFi, a novel vehicular middleware to identify and localize roadside WiFi APs that are located outside or inside buildings. Our work is motivated by the recent surge in availability of open WiFi access points (APs) that are enabling opportunistic data services to moving vehicles. Two key elements of CrowdWiFi that provide vehicles with opportunistic WiFi access include (a) an online compressive sensing component and (b) an offline crowd-sourcing module. Online compressive sensing (CS) techniques are primarily used to for the coarse-grained estimation of nearby APs along the driving route; here, the received signal strength (RSS) values are recorded at runtime, and the number and locations of APs are recovered immediately based on limited RSS readings. The offline crowdsourcing mechanism assigns the online CS tasks to crowd-vehicles and aggregates answers using a bipartite graphical model. This offline crowdsourcing executes at a crowd-server that iteratively infers the reliability of each crowd-vehicle from the aggregated sensing results and refines the estimation of APs using weighted centroid processing. Extensive simulation results and real testbed experiments confirm that CrowdWiFi can successfully reduce the number of measurements needed for AP recovery, while maintaining satisfactory counting and localization accuracy. In addition, the impact of CrowdWiFi middleware on WiFi handoff and data transmission applications is examined.
Suggested Citation
Di Wu, Qiang Liu, Yuan Zhang, Julie McCann, Amelia Regan and Nalini Venkatasubramanian (2014) “CrowdWiFi. efficient crowdsensing of roadside WiFi networks”, in Proceedings of the 15th international middleware conference on - middleware '14. ACM Press, pp. 229–240. Available at: 10.1145/2663165.2663329. conference paper
Impact of VSL location on capacity drop: A case of sag and tunnel bottlenecks
INTERNATIONAL SYMPOSIUM OF TRANSPORT SIMULATION (ISTS'18) AND THE INTERNATIONAL WORKSHOP ON TRAFFIC DATA COLLECTION AND ITS STANDARDIZATION (IWTDCS'18) - EMERGING TRANSPORT TECHNOLOGIES FOR NEXT GENERATION MOBILITY
Publication Date
January 1, 2018
Author(s)
Abstract
When there is upstream congestion the discharging flow-rate of a tunnel or sag bottleneck can drop, which leads to additional traffic jams. Therefore, control strategies such as variable speed limit (VSL) have been developed aiming to prevent or mitigate upstream traffic congestion. Understanding traffic dynamics at bottlenecks, especially the mechanism of capacity drop, is critical for developing such models. Many studies are centered on the control algorithm design of VSL. However, there are few studies that systematically anayze the effect that the VSL application area has on the control effectiveness. This paper extends to sag and tunnel bottlenecks the theoretical framework to analytically solve the optimal location of the speed limit application area (first developed in Martinez and Jin (2018)). Moreover, we prove that the optimization formulation can be simplified. Consequently, it can be applied to further bounded acceleration models than the constant one. Finally, for an open-loop control with a constant speed limit for the Kobotonoke tunnel bottleneck, we validate the analytic definition of optimal location by preventing capacity drop in numerical simulations. (C) 2018 The Authors. Published by Elsevier Ltd.
Suggested Citation
Irene Martinez and Wen-Long Jin (2018) “Impact of VSL location on capacity drop: A case of sag and tunnel bottlenecks”, in . Yoshii, T and Shiomi, Y and Kusakabe, T and Wada, K (ed.) INTERNATIONAL SYMPOSIUM OF TRANSPORT SIMULATION (ISTS'18) AND THE INTERNATIONAL WORKSHOP ON TRAFFIC DATA COLLECTION AND ITS STANDARDIZATION (IWTDCS'18) - EMERGING TRANSPORT TECHNOLOGIES FOR NEXT GENERATION MOBILITY. ELSEVIER SCIENCE BV (Transportation research procedia), pp. 12–19. Available at: 10.1016/j.trpro.2018.11.008.
published journal article
Elements of an ideal urban policy
KOREAN ECONOMIC REVIEW
Publication Date
January 1, 2013
Author(s)
Abstract
This paper sketches a number of elements of an ideal urban policy. The features of an ideal fiscal system are discussed, and the potential need for modifications to that system to account for special features of the urban economy are noted. The discussion also considers a number of policies that affect the spatial sizes of cities, the size and composition of their populations, and their industrial makeups.