MS Thesis
Archives: Research Products
conference paper
A general-purpose scheme to incorporate global ATIS strategies in real-time traffic control
Proceedings of the 90th annual meeting of the transportation research board
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Author(s)
Abstract
A general-purpose scheme that works with global Advanced Traveler Information Systems (ATIS) strategies is introduced for real-time traffic signal control. The system is (1) applicable under modern data technologies, (2) flexible in response to variations of traffic flows due to its non-cyclic feature, (3) operable on a network-wide and real-time basis, and (4) capable of conforming global ATIS strategies in the form of desired longer period green time ratios for intersection movement. The proposed system has a two-level hierarchical architecture: (1) strategy level and (2) control level. Considering the optimal states for a long-term period found in the strategy level, the optimal signal timings for a short-term period are calculated in the control level which consists of two steps: (1) queue weight update and (2) signal optimization. Based on the ratio of the cumulative green time to the desired green time is the first step to update the queue weights, which are then used in the optimization to find signal timings for minimum total delay. A parametric queue weight function is developed, discussed and evaluated. Numerical experiments demonstrate that the proposed system performs effectively and the resultant signal plans are close to the global ATIS strategies.
Suggested Citation
Inchul Yang and R. Jayakrishnan (2011) “A general-purpose scheme to incorporate global ATIS strategies in real-time traffic control”, in Proceedings of the 90th annual meeting of the transportation research board, p. 16p.Phd Dissertation
Compact Development and Gender Inequality: Do More Accessible and Walkable Built Environments Promote Gender Equality in Travel and Activity Space Behaviors?
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Author(s)
Abstract
Researchers have been concerned that suburban sprawl could reinforce gendered mobility patterns and lead to gendered differences in mobility. Previous studies also argued that the effectiveness of land use policy could be influenced by men and women’s different mobility patterns in response to built environments. To address these concerns, this dissertation uses the 2010-2012 California Household Travel Survey data and directly compares the within-household gendered travel and spatial behaviors for households with paired heads living in Southern California. The study examines whether built environments, including destination accessibility, design and walkability have different impacts on male and female heads’ daily travel and activity space behaviors and whether potential urban design can help improve gendered inequality in daily mobility.Based on negative binomial, Tobit, and feasible generalized least squares regressions, the results show that that male and female heads respond to built environments with different travel and spatial behaviors. Living in walkable and accessible areas is likely to encourage male heads to walk, reduce their dependence on driving, locate activity center close to home, and have spatially concentrated activities. Female heads tend to respond to walkable and accessible living environments with reducing automobile travel and with centering and confining their activities near residential neighborhoods. The negative binomial, Tobit, and binary logit regression analyses that investigate the influences of built environments on gendered inequality indicate that high walkability and regional accessibility are likely to reduce the gendered inequality in motorized travel distance and relax female heads’ spatial (and temporal) constraints relative to their husbands.This dissertation contributes to the policy debates by informing planners and feminist geographers that the effects of built environments can be heterogeneous even for men and women from similar backgrounds and compact design can be the key to gendered equity. Given that compact developments are being rapidly implemented in Southern California, this dissertation study is expected to help shape effective and efficient land use policies in the future.
Suggested Citation
Wan-Tzu Lo (2017) Compact Development and Gender Inequality: Do More Accessible and Walkable Built Environments Promote Gender Equality in Travel and Activity Space Behaviors?. Ph.D.. UC Irvine. Available at: https://escholarship.org/uc/item/134495m4 (Accessed: October 12, 2023).working paper
The Potential for Integrating GIS in Activity-Based Forecasting Models
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Author(s)
Working Paper
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Abstract
An increased interest in the development and implementation of activity-based modeling approaches has been evident in the ISTEA era given federal mandates to improve current modeling practice. Several activity-based alternatives to conventional regional forecasting are presented. Each of these approaches integrates household activities, land use distributions, regional demographics and transportation networks in a framework that explicitly recognizes the complexity of travel behavior in terms of temporal and spatial constraints, household interactions, transport accessibility and its inherent activity-derived basis. A brief evaluation of the temporal stability of the proposed basic unit of analysis, the household’s set of individual activity patterns, leads to a summary of a pattern-based generation model and the initial development of an activity-based microsimulation to replace the demand components of the conventional process.
Suggested Citation
Michael G. McNally (1997) The Potential for Integrating GIS in Activity-Based Forecasting Models. Working Paper UCI-ITS-WP-97-10, UCI-ITS-AS-WP-97-3. Institute of Transportation Studies, Irvine. Available at: https://escholarship.org/uc/item/2js9554x.working paper
Productivity Comparisons of Four Different Modes of Demand Responsive Service in Orange, California
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Author(s)
Working Paper
Areas of Expertise
Abstract
The Orange County Transit District (OCTD) has operated a community service transit program in the City of Orange, California since May of 1975. Because of an adverse court ruling and a subsequent successful appeal, this service underwent four modal changes. These four modes provide a unique opportunity for comparison. In order of implementation, they were: a demand-responsive Dial-A-Bus, a three-loop fixed route bus system, a two-loop fixed route bus system, and a demand-responsive Dial-A-Taxi system. Five performance indicators were used for the comparison, and the two demand-responsive systems were found more efficient and effective than the fixed route systems. The Dial-A-Taxi system, during its first three months of operation, compared very favorably to Dial-A-Bus. In addition, the Dial A-Taxi system continues to show monthly improvements on each indicator. There may be limited transferability of the information gained in this study, but the data suggests that Dial-A-Taxi can be very efficient and effective in serving cities or suburban areas with population densities of 5000 or less per square mile.
Suggested Citation
Al Hollinden and Rebecca Blair (1978) Productivity Comparisons of Four Different Modes of Demand Responsive Service in Orange, California. Working Paper UCI-ITS-WP-78-3. Institute of Transportation Studies, Irvine. Available at: https://escholarship.org/uc/item/7bv7q4ns.published journal article
Transit, employment and women on welfare1
Urban Geography
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Author(s)
Abstract
Inadequate transportation has emerged as a major barrier to employment for welfare recipients required to transition from public assistance to employment under welfare reform. Transportation is a particularly daunting barrier for single women without access to a household car. This study uses multivariate techniques to examine whether nearby transit access impacts the employment outcomes of this population in Los Angeles County. Results show that the level of transit service near a recipient’s home makes a moderate, yet statistically significant, contribution to increasing the probability of employment and transit use for work-related trips. However, recipients who use public transit face multiple problems, including overcrowding and infrequent service.
Suggested Citation
Paul M. Ong and Douglas Houston (2002) “Transit, employment and women on welfare1”, Urban Geography, 23(4), pp. 344–364. Available at: 10.2747/0272-3638.23.4.344.research report
High Occupancy Vehicle (HOV) System Analysis Tools: Statewide HOV Facility Performance Analysis
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Associated Project
Author(s)
Abstract
The two most common types of high occupancy vehicle (HOV) lanes in California are continuous access, prevalent in Northern California, and buffer-separated limited access, prevalent in Southern California. This report describes the evaluation of operational performance of HOV facilities in several regions in California with different access types as well as a before-after comparative study of California facilities where access types were converted in recent years. A set of performance measures were defined and selected to indicate how well the HOV facilities achieve intended goals – congestion relief, travel time saving, greater highway capacity. Additionally, an alternative methodology of indicating how well the operations perform in terms of the traffic flow fundamental diagrams was also adopted.
Suggested Citation
Kitae Jang, Ching-Yao Chan, Yao-Qiong Du, Lianyu Chu, Ming-Hsun Yang and Will Recker (2012) High Occupancy Vehicle (HOV) System Analysis Tools: Statewide HOV Facility Performance Analysis. Final Report UCB-0323. Institute of Transportation Studies, Irvine. Available at: https://escholarship.org/uc/item/6928d1mq.published journal article
ParkCrowd: Reliable crowdsensing for aggregation and dissemination of parking space information
IEEE Trans. Intell. Transport. Syst.
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Author(s)
Suggested Citation
Fengrui Shi, Di Wu, Dmitri I. Arkhipov, Qiang Liu, Amelia C. Regan and Julie A. McCann (2019) “ParkCrowd: Reliable crowdsensing for aggregation and dissemination of parking space information”, IEEE Trans. Intell. Transport. Syst., 20(11), pp. 4032–4044. Available at: 10.1109/tits.2018.2879036.conference paper
A calibration procedure for microscopic traffic simulation
Proceedings of the 2003 IEEE international conference on intelligent transportation systems
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Author(s)
Abstract
Simulation modeling is an increasingly popular and effective tool for analyzing transportation problems that are not amendable to study by other means. For any simulation study, model calibration is a crucial step to obtaining any results from analysis. This paper presents a systematic, multi-stage calibration and validation, procedure for microscopic simulation models. The procedure is demonstrated in a calibration, study with a corridor network in the southern California. The model validation results for the study network are also summarized.
Suggested Citation
LY Chu, HX Liu, JS Oh and W Recker (2003) “A calibration procedure for microscopic traffic simulation”, in Proceedings of the 2003 IEEE international conference on intelligent transportation systems. IEEE, pp. 1574–1579. Available at: 10.1109/itsc.2003.1252749.conference paper
A methodological framework for integrated control in corridor networks
ITSC 2001. 2001 IEEE intelligent transportation systems. Proceedings (cat. No.01TH8585)
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Author(s)
Abstract
This paper presents a framework for an integrated control system, with an embedded travel demand model that reflects drivers’ response to the control strategy. The integrated control problem is formulated as an optimal control problem of determining such control variables as the on-ramp metering rates, the minimum green duration, the maximum green duration (or force off), background cycle length (if coordinated) and the critical time gap for vehicle actuated urban signals, subject to the control constrains, so as to optimize a performance index. The approach takes into consideration the interaction between the control strategy and drivers’ response to it recognizing the later as a critical parameter to the performance of the system. Finally, a numerical method is proposed for the solution of the formulated optimal control problem.