published journal article

Shared E-Scooter Trajectory Analysis During the COVID-19 Pandemic in Austin, Texas

Transportation Research Record

Publication Date

April 1, 2023

Author(s)

Matthew Dean, Natalia Zuniga-Garcia

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Abstract

By March of 2020, most cities worldwide had enacted stay-at-home public health orders to slow the spread of COVID-19. Restrictions on nonessential travel had extensive impacts across the transportation sector in the short term. This study explores the effects of COVID-19 on shared e-scooters by analyzing route trajectory data in the pre- and during-pandemic periods in Austin, TX, from a single provider. Although total shared e-scooter trips decreased during the pandemic, partially owing to vendors pulling out of the market, this study found average trip length increased, and temporal patterns of this mode did not meaningfully change. A count model of average daily trips by road segment found more trips on segments with sidewalks and bus stops during the pandemic than beforehand. More trips were observed on roads with lower vehicle miles traveled and fewer lanes, which might suggest more cautious travel behavior since there were fewer trips in residential neighborhoods. Stay-at-home orders and vendor e-scooter rebalancing operations inherently influence and can limit trip demand, but the unique trajectory data set and analysis provide cities with information on the road design preferences of vulnerable road users.

Suggested Citation

Matthew D. Dean and Natalia Zuniga-Garcia (2023) “Shared E-Scooter Trajectory Analysis During the COVID-19 Pandemic in Austin, Texas”, Transportation Research Record, 2677(4), pp. 432–447. Available at: 10.1177/03611981221083306.

conference paper

RAMP: Impact of rule based aggregator business model for residential microgrid of prosumers including distributed energy resources

ISGT 2014

Publication Date

February 1, 2014

Author(s)

Mohammad Al Faruque

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Suggested Citation

Mohammad Abdullah Al Faruque (2014) “RAMP: Impact of rule based aggregator business model for residential microgrid of prosumers including distributed energy resources”, in ISGT 2014. IEEE. Available at: 10.1109/isgt.2014.6816387.

published journal article

Suitable Bus Stop Locations for a Proposed Bus Rapid Transit Corridor in a Developing Country City: An Analytical Hierarchy Process Approach

Transportation in Developing Economies

Publication Date

March 14, 2023

Author(s)

Md Musfiqur Rahman Bhuiya, Rezwana Rafiq, Khandaker Nabid Md Morshed, M. Imtiaz Rahman

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Abstract

Bangladesh is one of the world’s most densely populated developing countries, and so is its capital Dhaka, where ever-growing travel demand is causing congestion and numerous other transportation problems. To improve the situation, the “Strategic Transport Plan for Dhaka (STP)” was conceptualized in 2005 with the plan of developing mass transit systems (buses and rail), which was revised in 2016. The revised STP proposes two BRT bus routes for Dhaka city: BRT Line 3 and 7. Bus stops on the proposed routes are the ultimate point locations where people at large will access these BRT services. Therefore, determining the locations of bus stops is crucial for these proposed routes’ overall efficiency and accessibility. In this study, we proposed a bus stop selection technique for the BRT Line 3 in Dhaka, which considers multi-variate influencing factors, including travel demand, population density, land use, accessibility of pedestrians, and accessibility of rickshaws. We collected data on these factors through a field survey for 77 intersections along the study route. After that, a composite score is assigned for each study intersection based on the five factors’ relative value and priority weights obtained via the Analytical Hierarchical Process technique. Finally, based on the composite score and selection criteria, we suggested 25–40 intersections for suitable bus stop locations along the study route. The methodology used in this study to select suitable bus stop locations will provide citizens with better utilization and transit experience as envisioned by the BRT routes.

Suggested Citation

Md Musfiqur Rahman Bhuiya, Rezwana Rafiq, Khandaker Nabid Md Morshed and M. Imtiaz Rahman (2023) “Suitable Bus Stop Locations for a Proposed Bus Rapid Transit Corridor in a Developing Country City: An Analytical Hierarchy Process Approach”, Transportation in Developing Economies, 9(1), p. 10. Available at: 10.1007/s40890-023-00179-6.

published journal article

Estimating impacts of emission specific characteristics on vehicle operation for quantifying air pollutant emissions and energy use

Journal of Traffic and Transportation Engineering (English Edition)

Publication Date

June 1, 2017

Author(s)

Nesamani Kalandiyur, Jean-Daniel Saphores, Michael McNally, R. (Jay) Jayakrishnan

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Suggested Citation

K.S. Nesamani, Jean-Daniel Saphores, Michael G. McNally and R. Jayakrishnan (2017) “Estimating impacts of emission specific characteristics on vehicle operation for quantifying air pollutant emissions and energy use”, Journal of Traffic and Transportation Engineering (English Edition), 4(3), pp. 215–229. Available at: 10.1016/j.jtte.2017.05.007.

published journal article

Predicting the market penetration of electric and clean-fuel vehicles

Science of The Total Environment

Publication Date

June 1, 1993

Author(s)

Thomas Golob, Ryuichi Kitamura, Mark Bradley, David Bunch

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Abstract

Air quality in Southern California and elsewhere could be substantially improved if some gasoline-powered personal vehicles were replaced by vehicles powered by electricity or alternative fuels, such as methanol, ethanol, propane, or compressed natural gas. Quantitative market research information about how consumers are likely to respond to alternative-fuel vehicles is critical to the development of policies aimed at encouraging such technological change. In 1991, a three-phase stated preference (SP) survey was implemented in the South Coast Air Basin of California to predict the effect on personal vehicle purchases of attributes that potentially differentiate clean-fuel vehicles from conventional gasoline (or diesel) vehicles. These attributes included: limited availability of refueling stations, limited range between refueling or recharging, vehicle prices, fuel operating costs, emissions levels, multiple-fuel capability and performance. Respondents were asked to choose one vehicle from each of five sets of hypothetical clean-fuel and conventional gasoline vehicles, each vehicle defined in terms of attributes manipulated according to a specific experimental design. Discrete choice models, such as the multinominal logit model, are then used to estimate how the values of the attribute levels influence purchase decisions. The SP survey choice sets were customized to each respondent’s situation, as determined in the preceding phase of the survey. The final phase of the survey involved fuel-choice SP tasks for multi-fuel vehicles that can run on either clean fuels or gasoline. Preliminary results from a pilot sample indicate that the survey responses are plausible and will indeed be useful for forecasting.

Suggested Citation

Thomas F Golob, Ryuichi Kitamura, Mark Bradley and David S Bunch (1993) “Predicting the market penetration of electric and clean-fuel vehicles”, Science of The Total Environment, 134(1-3), pp. 371–381. Available at: 10.1016/0048-9697(93)90367-f.

published journal article

Automated time activity classification based on global positioning system (GPS) tracking data

Environmental health : a global access science source

Publication Date

November 1, 2011

Author(s)

Jun Wu, Chengsheng Jiang, Doug Houston, Dean Baker, Ralph Delfino

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Suggested Citation

Jun Wu, Chengsheng Jiang, Douglas Houston, Dean Baker and Ralph Delfino (2011) “Automated time activity classification based on global positioning system (GPS) tracking data”, Environmental health : a global access science source, 10(1). Available at: 10.1186/1476-069x-10-101.

research report

Resilience and Validation of GNSS PNT Solutions

Publication Date

November 20, 2023

Author(s)

Todd E. Humphreys, Qi Alfred Chen, Umit Ozguner, Charles Toth

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Abstract

Highly automated transportation systems rely on a steady stream of signals and information from external sources for localization, route planning, perception, and general situational awareness. This includes reliance on positioning, navigation, and timing (PNT) information: Location is essential autonomous navigation and planning; and accurate timing is a precondition for on-board sensor fusion, cooperative control, and management based on information from other vehicles or the infrastructure. It is crucial to identify schemes for GNSS signal authentication and resilience that are well-suited for highly autonomous vehicles (HAVs). HAVs require PVT sensing techniques that are resilient to unusual natural or accidental events and secure against deliberate attack.

Suggested Citation

Todd E. Humphreys, Qi Alfred Chen, Umit Ozguner and Charles Toth (2023) Resilience and Validation of GNSS PNT Solutions. Final Report. Available at: https://rosap.ntl.bts.gov/view/dot/72661.

published journal article

A generalized diffusion model for preference and response time: Application to ordering mobility-on-demand services

Transportation Research Part C: Emerging Technologies

Publication Date

December 1, 2020

Author(s)

Jiangbo (Gabe) Yu, Michael Hyland

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Abstract

The goal of this research study is to model user preferences and response times (RTs) jointly in the context of Mobility-on-Demand (MOD) services under different MOD operator pricing schemes, information frames, and pressure levels. MOD operators’ information provision, delay, and vehicle allocation strategies influence users’ preferences and RTs, which, in turn, affect which operational and information provision strategies are optimal for MOD operators. Evidence shows that preferences and RTs are sensitive to precedent decisions, information frames, risk, and time pressure. These dynamic interplaying factors are challenging to capture using a traditional discrete choice modeling framework. Hence, this study proposes a generalized diffusion model based on Decision Field Theory (DFT), multi-attribute Prospect Theory (PT), and Random Utility Theory to model these various interplaying factors. This study applies the proposed modeling approach in the context of ordering Shared-use Automated Vehicle Mobility Services (SAMS). Sensitivity analyses explore the impacts of various inputs and model parameters such as initial waiting time estimate, updated waiting time estimate, time pressure, loss aversion, and value-of-time on preferences and RTs. The proposed model can provide value to MOD operators in terms of information provision and pricing strategies. Moreover, the proposed model can assist policymakers and planners interested in the system impacts of MOD services and regulating MOD information provision and pricing strategies. The modeling framework can extend to other applications where multiple sub-decisions are necessary to make a single (travel) choice under information update, framing, risk, and time pressure.

Suggested Citation

Jiangbo Yu and Michael F. Hyland (2020) “A generalized diffusion model for preference and response time: Application to ordering mobility-on-demand services”, Transportation Research Part C: Emerging Technologies, 121, p. 102854. Available at: 10.1016/j.trc.2020.102854.

conference paper

On the existence of stationary states in general road networks

21st international symposium on transportation and traffic theory

Publication Date

January 1, 2015

Author(s)

Wenlong Jin

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Abstract

Our daily driving experience and empirical observations suggest that traffic patterns in a road network are relatively stationary during peak periods. In numerous transportation network studies, there has been an implicit conjecture that stationary states exist in a network when origin demands, route choice proportions, and destination supplies are constant. In this study, we first rigorously formulate the conjecture within the framework of a network kinematic wave theory with an invariant junction model. After defining stationary states, we derive a system of algebraic equations in 3-tuples of stationary link flow-rates, demands, and supplies. We then introduce a new definition of junction critical demand levels based on effective demands and supplies. With a map in critical demand levels, we show that its fixed points and, therefore, stationary states exist with the help of Brouwer’s fixed point theorem. For two simple road networks, we show that the map is well-defined and can be used to solve stationary states with a brute-force method. Finally we summarize the study and present some future extensions and applications. (C) 2015 The Authors. Published by Elsevier B.V.

Suggested Citation

Wen-Long Jin (2015) “On the existence of stationary states in general road networks”, in . Kuwahara, M and Kita, H and Asakura, Y (ed.) 21st international symposium on transportation and traffic theory. ELSEVIER SCIENCE BV (Transportation research procedia), pp. 689–703. Available at: 10.1016/j.trpro.2015.06.036.

conference paper

Freeway incident detection using artificial neural networks

Proceedings, International Conference on Artificial Intelligence Applications in Transportation Engineering

Publication Date

January 1, 1998

Author(s)

Stephen Ritchie, Kelvin Cheu, Will Recker

Suggested Citation

S. G. Ritchie, Ruey L. Cheu and W. W. Recker (19982) “Freeway incident detection using artificial neural networks”, in Proceedings, International Conference on Artificial Intelligence Applications in Transportation Engineering. San Bueneventura, California.