published journal article

Ground vehicle navigation in GNSS-Chal­len­ged environments using signals of opportunity and a closed-loop Map-Match­ing approach

IEEE Trans. Intell. Transport. Syst.

Publication Date

July 1, 2020

Author(s)

Mahdi Maaref, Zaher Kassas

Abstract

A ground vehicle navigation approach in a global navigation satellite system (GNSS)-challenged environments is developed, which uses signals of opportunity (SOPs) in a closed-loop map-matching fashion. The proposed navigation approach employs a particle filter that estimates the ground vehicle’s state by fusing pseudoranges drawn from ambient SOP transmitters with road data stored in commercial maps. The problem considered assumes the ground vehicle to have a priori knowledge about its initial states as well as the position of SOPs. The proposed closed-loop approach estimates the vehicle’s states for subsequent time as it navigates without the GNSS signals. In this approach, a particle filter is employed to continuously estimate the vehicle’s position and velocity along with the clock error states of the vehicle-mounted receiver and SOP transmitters. The simulation and experimental results with cellular long-term evolution (LTE) SOPs are presented, evaluating the efficacy and accuracy of the proposed framework in different driving environments. The experimental results demonstrate a position root-mean-squared error (RMSE) of: 1.6 m over a 825-m trajectory in an urban environment with five cellular LTE SOPs, 3.9 m over a 1.5-km trajectory in a suburban environment with two cellular LTE SOPs, and 3.6 m over a 345-m trajectory in a challenging urban environment with two cellular LTE SOPs. It is demonstrated that incorporating the proposed map-matching algorithm reduced the position RMSE by 74.88%, 58.15%, and 46.18% in these three environments, respectively, from the RMSE obtained by an LTE-only navigation solution.

Suggested Citation
Mahdi Maaref and Zaher M. Kassas (2020) “Ground vehicle navigation in GNSS-Chal­len­ged environments using signals of opportunity and a closed-loop Map-Match­ing approach”, IEEE Trans. Intell. Transport. Syst., 21(7), pp. 2723–2738. Available at: 10.1109/tits.2019.2907851.

published journal article

Deriving Intersection Turning Movements Via Path Flow Estimator

Journal of the Eastern Asia Society for Transportation Studies

Publication Date

October 1, 2003

Author(s)

Suggested Citation
Piya Chootinan, Anthony Chen, Ming S. Lee and Will RECKER (2003) “Deriving Intersection Turning Movements Via Path Flow Estimator”, Journal of the Eastern Asia Society for Transportation Studies, 5. Available at: https://easts.info/2003journal/papers/1140.pdf.

policy brief

Policy Considerations for Advancing Bidirectional Electric Vehicle Charging in California

Abstract

Electric vehicles (EVs) are proliferating rapidly in California, with now over 1.8 million operating in the state. Battery charging loads can stress local electricity distribution feeders, particularly in the early evening when power use typically peaks. Many EVs now, and many more in the future will have bidirectional or vehicle-to-grid (V2G) capability, meaning their large battery packs can be discharged for a variety of uses—from providing backup power to homes and businesses to providing a larger set of grid services including supporting local voltages and 60 Hertz cycle frequency. This brief provides an overview of bidirectional charging and policy considerations for supporting its increased use.

Suggested Citation
Timothy Lipman (2024) Policy Considerations for Advancing Bidirectional Electric Vehicle Charging in California. Policy Brief. UC ITS. Available at: https://doi.org/10.7922/g24t6gq9.

conference paper

A SEM analysis of the impact of urban form and gasoline prices on vehicle use: An application to southern California

Proceedings of the 95th annual meeting of the transportation research board

Publication Date

January 1, 2016

Abstract

This paper relies on generalized structural equation modeling (SEM) to explore the relationship between land use, gasoline prices, and driving. The authors analyze data from the Southern California subsample of the 2009 National Household Travel Survey (NHTS), which has a quasi-experimental nature thanks to large exogenous variations in gasoline prices during the conduct of the NHTS. The authorsâ?? joint models of residential urban form, vehicle efficiency choice, and vehicle use account for residential self-selection and endogeneity of vehicle preferences in order to explain vehicle miles traveled (VMT) for both work and non-work trips. Residential urban form is treated as a latent construct that reflects variables such as population density, land use diversity and distance to employment centers. The authorsâ?? results suggest that in the short run, households drive 0.15% less for non-work trips when gas prices increase by 1%, while work trips are not responsive to gasoline price changes. Moreover, the direct effect of residential urban form on driving is statistically significant for total and non-work VMT, but it has no impact on work trips. The authors also find that owners of more fuel efficient vehicles tend to be more educated, Asian and younger (under 30). Moreover, households in low density neighborhoods are more likely to have a higher income, to be older than 65 and Caucasian. Finally, the results show that accounting for the nature of trips is important for understanding the short term price elasticity of travel.

Suggested Citation
Harya S. Dillon, Jean-Daniel Saphores and Marlon Boarnet (2016) “A SEM analysis of the impact of urban form and gasoline prices on vehicle use: An application to southern California”, in Proceedings of the 95th annual meeting of the transportation research board, p. 19p.

working paper

A Knowledge-Based Approach to Improve Urban Transportation Decision Making

Abstract

This paper describes a microcomputer-based tool that has been developed to facilitate acquisition and improvement of skills in urban transportation decision making. This tool interfaces with a complex gaming-simulation model and involves a knowledge-based expert system, built using programming techniques from the field of artificial intelligence. The gaming-simulation model synthesizes the consequences of the decision-making activities of a Transportation Director (model user) in a city with urgent transportation needs. The role of the expert system is to advise users on how to achieve multiple street and transit system goals over a ten-year period, during which time several hundred decisions must be made. Each year, the expert system suggests actions to the user that can be used as possible inputs to the following year’s budgetary and decision-making process. Results of limited tests to date indicate that this expert system permits achievement of performance levels that very few unassisted users can attain.

Suggested Citation
Stephen G. Ritchie and C. Yeh (1987) A Knowledge-Based Approach to Improve Urban Transportation Decision Making. Working Paper UCI-ITS-WP-87-9. Institute of Transportation Studies, Irvine. Available at: https://escholarship.org/uc/item/4dg131zw.

published journal article

Gap-based transit assignment algorithm with vehicle capacity constraints: Simulation-based implementation and large-scale application

Transportation Research Part B: Methodological

Publication Date

November 1, 2016

Author(s)

öMer Verbas, Hani Mahmassani, Michael Hyland
Suggested Citation
Omer Verbas, Hani S. Mahmassani and Michael F. Hyland (2016) “Gap-based transit assignment algorithm with vehicle capacity constraints: Simulation-based implementation and large-scale application”, Transportation Research Part B: Methodological, 93, pp. 1–16. Available at: 10.1016/j.trb.2016.07.002.

published journal article

Bunching in real-estate markets: Regulated building heights in New York City

Journal of Urban Economics

Publication Date

September 1, 2024

Author(s)

Jan Brueckner, David Leather, Miguel Zerecero

Abstract

This paper presents a real-estate application of the bunching methodology widely used in other areas of applied microeconomics. The focus is on regulated building heights in New York City, where developers can exceed a parcel’s regulated height by incurring additional costs. Using the bunching methodology, we estimate the magnitude of these extra costs, with the results showing a modest increase in the marginal cost of floor space beyond the regulated building height. We use these estimates to predict the additional floor space that would be created by complete removal of building-height regulation in NYC. While this last exercise is circumscribed by our focus on a limited number of zoning categories, the results suggest that New York could secure notably more housing through lighter height regulation.

Suggested Citation
Jan K. Brueckner, David Leather and Miguel Zerecero (2024) “Bunching in real-estate markets: Regulated building heights in New York City”, Journal of Urban Economics, 143, p. 103683. Available at: 10.1016/j.jue.2024.103683.

conference paper

Factors affecting speed of motor vehicles on urban arterials: Case of chennai, India

Proceedings of the 85th annual meeting of the transportation research board

Publication Date

January 1, 2006

Abstract

It is important to understand the factors affecting speed in a link to design a better roadway. The aim of this study was to identify the extend speed is influenced by geometric design elements, traffic characteristics and roadway characteristics, particularly in urban arterial streets. This study is distinct from previous research that it analysis how speed is affected in heterogeneous traffic conditions. In this study second-by-second speed data is collected using Global Positioning System (GPS). Initial analysis showed that more than 50% of time in a trip spent at the speed below 25 km/h. Time spent in both acceleration and deceleration mode was about 65%, which explains the frequent variation of speed in a trip. A multiple linear regression model was constructed to understand the causes of variation in speed. The effect of traffic characteristics and roadside characteristics has significant influence over speed when compared to geometric characteristics. Among traffic characteristics, total volume and time spent in creep mode have significant influence over speed. In roadside characteristics, both commercial and pedestrian activities were negatively correlated. Followed by lane width, pedestrian interference, stop duration and commercial landuse are significant variables. These variables explained about 48% of variations in speed. Variables such as grade level, share of slow moving vehicles, time of the day and on-street parking didnâ??t show up in the model. However, they have shown the sign of influence on speed.

Suggested Citation
Michael G. McNally, R. Jayakrishnan, Nesamani Subramanian Kalandiyur and K.P. Subramanian (2006) “Factors affecting speed of motor vehicles on urban arterials: Case of chennai, India”, in Proceedings of the 85th annual meeting of the transportation research board, p. 23p. Available at: https://trid.trb.org/view/777779.

published journal article

On the structure of weekly activity/travel patterns

Transportation Research Part A: Policy and Practice

Publication Date

December 1, 2003

Abstract

Understanding the process of activity scheduling is a critical pre-requisite to an understanding of changes in travel behavior. To examine this process, a computerized survey instrument was developed to collect household activity scheduling data. The instrument is unique in that it records the evolution of activity schedules from intentions to final outcomes for a weekly period. This paper summarizes an investigation of the structure of activity/travel patterns based on data collected from a pilot study of the instrument. The term “structure” refers to the sequence by which various activities enter one’s daily activity scheduling process. Results of the empirical analyses show that activities of shorter duration were more likely to be opportunistically inserted in a schedule already anchored by their longer duration counterparts. Additionally, analysis of travel patterns reveals that many trip-chains were formed opportunistically. Travel time required to reach an activity was positively related to the scheduling horizon for the activity, with more distant stops being planned earlier than closer locations. (C) 2003 Elsevier Ltd. All rights reserved.

Suggested Citation
Ming S. Lee and Michael G. McNally (2003) “On the structure of weekly activity/travel patterns”, Transportation Research Part A: Policy and Practice, 37(10), pp. 823–839. Available at: 10.1016/s0965-8564(03)00047-8.