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Full-Text Articles in Transportation Engineering

Analysis Of Traffic Conflicts With Right Turning Vehicles At Unsignalized Intersections In Suburban Areas, Abbas Sheykhfard, Farshidreza Haghighi, Sarah Bakhtiari, Sara Moridpour, Kun Xie, Grigorios Fountas Jan 2024

Analysis Of Traffic Conflicts With Right Turning Vehicles At Unsignalized Intersections In Suburban Areas, Abbas Sheykhfard, Farshidreza Haghighi, Sarah Bakhtiari, Sara Moridpour, Kun Xie, Grigorios Fountas

Civil & Environmental Engineering Faculty Publications

Right-turn collisions at intersections are one of the most dominant crash types in suburban areas, especially at unsignalized intersections. There is, however, a lack of comprehensive research on the speed patterns of vehicles during right-turn manoeuvres and their impact on crashes. To provide an in-depth investigation of the factors determining the safety of right-turn manoeuvres, driving behaviour data were collected through an instrumented vehicle study. Using this data, binary logistic regression models were developed to identify the factors affecting the probability of Vehicle-Vehicle (V-V) and Vehicle-Pedestrian (V-P) conflicts at six suburban intersections in Babol, Iran, during right-turn stage manoeuvres. In …


Implications Of Alternative Communications And Sensing Technologies For Implementing Variable Speed Limit Control Through Connected Vehicles: Sag Curve As A Case Study, Reza Vatani Nezafat, Mecit Cetin, Elizabeth Williams, George F. List Jan 2024

Implications Of Alternative Communications And Sensing Technologies For Implementing Variable Speed Limit Control Through Connected Vehicles: Sag Curve As A Case Study, Reza Vatani Nezafat, Mecit Cetin, Elizabeth Williams, George F. List

Civil & Environmental Engineering Faculty Publications

Connected vehicles (CVs) will enable various applications to improve traffic flow. This paper's focus is to investigate how the potential implementation of variable speed limit (VSL) through different types of communication and sensing technologies on CVs makes it possible to mitigate congestion at a sag curve bottleneck. A VSL algorithm is developed and implemented in a simulation environment for controlling the inflow of vehicles to a sag curve to minimize delays and increase throughput. Both vehicle-to-vehicle (V2V) and infrastructure-to-vehicle (I2V) options for CVs are investigated when implementing the VSL control strategy in a simulation environment. Also, for measuring traffic density …


An Integrated Framework For Establishing Long-Term Transportation Management Strategies Promoting Sustainable Urban Growth, M Imtiaz Rahman Jan 2024

An Integrated Framework For Establishing Long-Term Transportation Management Strategies Promoting Sustainable Urban Growth, M Imtiaz Rahman

Graduate Theses, Dissertations, and Problem Reports (ETD)

Urban land areas are experiencing a more rapid expansion compared to their population growth on a global scale. This phenomenon, known as urban sprawl, is characterized by low-density development in the outskirts of cities. This unplanned urban growth leads to changing urban transportation patterns, posing a threat to sustainable development. In response, government agencies implement growth management practices, with transportation management strategies playing a crucial role in achieving sustainable urban growth. However, developing effective growth management strategies is difficult because of several challenges, including limited understanding of the key influencing factors, the complex interdependencies among these factors, and the uncertainties …


Reducing Food Scarcity: The Benefits Of Urban Farming, S.A. Claudell, Emilio Mejia Dec 2023

Reducing Food Scarcity: The Benefits Of Urban Farming, S.A. Claudell, Emilio Mejia

Journal of Nonprofit Innovation

Urban farming can enhance the lives of communities and help reduce food scarcity. This paper presents a conceptual prototype of an efficient urban farming community that can be scaled for a single apartment building or an entire community across all global geoeconomics regions, including densely populated cities and rural, developing towns and communities. When deployed in coordination with smart crop choices, local farm support, and efficient transportation then the result isn’t just sustainability, but also increasing fresh produce accessibility, optimizing nutritional value, eliminating the use of ‘forever chemicals’, reducing transportation costs, and fostering global environmental benefits.

Imagine Doris, who is …


Decoding Usage And Adoption Behavior Of The Low-Carbon Transportation Market: An Ai-Driven Exploration, Vuban Chowdhury Dec 2023

Decoding Usage And Adoption Behavior Of The Low-Carbon Transportation Market: An Ai-Driven Exploration, Vuban Chowdhury

Graduate Theses and Dissertations

The transportation sector stands as a significant contributor to greenhouse gas emissions in the United States, with its environmental impact steadily escalating over the past few decades. This has prompted government agencies to facilitate the adoption and usage of low-carbon transportation (LCT) options as alternatives to fossil-fuel-powered transportation. LCTs include modes of transportation that minimize the overall carbon footprint of the transportation sector by relying on energy sources that are environmentally sustainable. These sustainable transportation options have also garnered significant interest in the transportation research community. For government agencies and researchers alike, a comprehensive understanding of the adoption and usage …


Determining The Effect Of The Presence Of Food Deserts On The Number Of Crashes In Census Tracts In Arkansas, Lizbeth Juarez-Bartolo Dec 2023

Determining The Effect Of The Presence Of Food Deserts On The Number Of Crashes In Census Tracts In Arkansas, Lizbeth Juarez-Bartolo

Graduate Theses and Dissertations

Food deserts, areas with limited access to grocery stores which sell fresh produce, dairy, and meats, are a growing concern in many communities. The presence of a food desert is known to cause great impacts on the physical health of the people residing within them, but there is little to no research on a food desert’s influence on the traffic safety of the location in which it encompasses. Based on previous studies into food deserts, studies suggest that food inaccessibility is mostly felt by rural residents. Since rural residents must travel farther distances on more hazardous rural roadways to access …


System-Of-Systems Integration For Civil Infrastructures Resiliency Toward Multihazard Events, Vahid Balali Aug 2023

System-Of-Systems Integration For Civil Infrastructures Resiliency Toward Multihazard Events, Vahid Balali

Mineta Transportation Institute

Civil infrastructure systems—facilities that supply principal services, such as electricity, water, transportation, etc., to a community—are the backbone of modern society. These systems are frequently subject to multi-hazard events, such as earthquakes. The poor resiliency of these infrastructures results in many human casualties and significant economic losses every year. An outline of a holistic view that considers how different civil infrastructure systems operate independently and how they interact and communicate with each other is required to have a resilient infrastructure system. More specifically a systems engineering approach is required to enable infrastructure to remain resilient in the case of extreme …


Fiber-Based Seismic Damage And Collapse Assessment Of Reinforced Concrete Single-Column Pier-Supported Bridges Using Damage Indices, Yu-Fu Ko, Jessica Gonzalez Aug 2023

Fiber-Based Seismic Damage And Collapse Assessment Of Reinforced Concrete Single-Column Pier-Supported Bridges Using Damage Indices, Yu-Fu Ko, Jessica Gonzalez

Mineta Transportation Institute

Near-fault earthquakes can have major effects on transportation systems due to the structural damage they impose on bridges. Therefore, it is imperative to assess the seismic damage of bridges appropriately, and this research focuses on reinforced concrete (RC) bridges. This research advances the seismic performance assessment of RC single-column pier-supported bridges with flexural failure under near-fault ground motion by use of ductility coefficients and damage indices. The methodology included modeling fiber-based nonlinear beam-column elements to simulate the damage development process of RC bridge piers under earthquake loadings, considering the global buckling of longitudinal steel bars, examining the cracking and spalling …


Extending The Service-Life Of Bridges Using Sustainable And Resilient Abutment Systems: An Experimental Approach To Electrochemical Characterization Of Lightweight Mechanically Stabilized Earth, Fariborz M. Tehrani, Kenneth L. Fishman, Farmehr M. Dehkordi Jul 2023

Extending The Service-Life Of Bridges Using Sustainable And Resilient Abutment Systems: An Experimental Approach To Electrochemical Characterization Of Lightweight Mechanically Stabilized Earth, Fariborz M. Tehrani, Kenneth L. Fishman, Farmehr M. Dehkordi

Mineta Transportation Institute

Bridges are critical components of transportation infrastructure. This research addresses the need to extend the service life of bridges by improving the safety and reliability of bridge abutments and reducing their life-cycle cost and footprints. Mechanically stabilized earth (MSE) is a known strategy to enhance the economy and performance of bridge abutments. In addition, the application of rotary-kiln-manufactured lightweight aggregate backfills improves the performance of MSE bridge abutments with a leaner structural system. Such improvements include a reduction of structural demands due to a lower density, free drainage of granular materials, a high internal friction angle, less settlement with no …


Effectiveness Of Integrated Traffic Management Of Military Police And Traffic Police In Reducing Drive Speed N Arterial Roads: An Experimental Study, Teguh Patriot Jun 2023

Effectiveness Of Integrated Traffic Management Of Military Police And Traffic Police In Reducing Drive Speed N Arterial Roads: An Experimental Study, Teguh Patriot

CSID Journal of Infrastructure Development

The Indonesian National Police Traffic Corps (KORLANTAS POLRI) and the Army Staff and Command School (SESKOAD) conducted a joint study in early March 2023 to reduce the number of traffic accident victims by implementing traffic regulations by the Military Police and Traffic Police. One of the methods used by KORLANTAS POLRI is the installation of ETLE speed cameras on Jakarta toll roads, such as Cikampek, Jagorawi, Bitung, and others. At the end of 2022, 75 additional speed cameras had been installed on arterial roads in Jakarta.

The purpose of this study is to analyze the effectiveness …


Pavement Condition Survey Using Drone Technology, Lerose Lane, Dingxin Cheng Jun 2023

Pavement Condition Survey Using Drone Technology, Lerose Lane, Dingxin Cheng

Mineta Transportation Institute

Timely repairs of pavement defects are essential in protecting both public road and highway systems. Identification of pavement distresses is necessary for planning pavement repairs. This has previously been performed by engineers surveying the roadways visually in the field. As drone usage has progressed, it has become clear that drones are a valuable tool to enhance visual documentation, improve project communication, and provide various data for processing. The use of drone technology has improved both the speed and accuracy of capturing data. Available software has allowed the data to be processed and analyzed in an office environment. This report summarizes …


The Effect Of Four Decades Of Deregulation On Competition And Productivity Of The U.S. Freight Transportation Industry, Seungjae Shin May 2023

The Effect Of Four Decades Of Deregulation On Competition And Productivity Of The U.S. Freight Transportation Industry, Seungjae Shin

Theses and Dissertations

This study reviews the competition and productivity of the U.S. freight transportation industry for the past 41 years. This study investigated the trends of HHI market concentration index values and labor productivity values of rail and truck sectors and tried to find any relationships between the two values in the separate periods before and after the abolishment of the ICC. This study also investigated how the existence of a regulatory body impacted productivity of the freight transportation industry by using a Cobb Douglas production function on annual financial statement data in the U.S. stock exchange market. This study found that: …


Experimental Investigation Of The Self-Healing Potential Of Bacteria For Sustainable Concrete Structures, Pitiporn Asvapathanagul, Simone Galano, Andrea Calabrese, Mehran Rahmani, Maggie Ly, Daniela Flores, Michael Hernandez, Nicholas Banuelos May 2023

Experimental Investigation Of The Self-Healing Potential Of Bacteria For Sustainable Concrete Structures, Pitiporn Asvapathanagul, Simone Galano, Andrea Calabrese, Mehran Rahmani, Maggie Ly, Daniela Flores, Michael Hernandez, Nicholas Banuelos

Mineta Transportation Institute

Although concrete is the most widely used building material in the world, its limited tensile strength makes cracking a common phenomenon in concrete elements. This study investigates the potential of autonomous self-healing as an eco-friendly and lowcost method to increase the durability of concrete. The crack-healing potential of different types of high-alkaline-tolerant bacteria or calcite-precipitation microorganisms is investigated. High-alkaline-tolerant bacteria and calcite-precipitation microorganisms were used to retrofit lab-fractured concrete samples. The samples healed with each of these bacteria groups were cast and tested under compressive load up to failure to measure the compressive strength of the concrete samples. The outcomes …


Preconstruction Support Cost Hours Estimating On Caltrans Pavement Rehabilitation Projects, Nigel Blampied, Tariq Shehab, Elhami Nasr, Laxmi Sindhu Samudrala May 2023

Preconstruction Support Cost Hours Estimating On Caltrans Pavement Rehabilitation Projects, Nigel Blampied, Tariq Shehab, Elhami Nasr, Laxmi Sindhu Samudrala

Mineta Transportation Institute

Because the construction phase accounts for the majority of project costs for pavement rehabilitation projects, most research on infrastructure project cost estimating focuses on that phase, rather than on the preconstruction phases. Nevertheless, costs incurred prior to construction, referred to in this report as "preconstruction costs" are significant and worthy of consideration (See Section 2.1 of the report for a more detailed and precise definition of preconstruction). In the 20202021 fiscal year, for instance, the California Department of Transportation (Caltrans) spent more than $169 million on preconstruction work for pavement rehabilitation projects. This report presents the results of a study …


Historic Downtown Streetscape Plan Price City, Utah, Patricia Beckert May 2023

Historic Downtown Streetscape Plan Price City, Utah, Patricia Beckert

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

The idea of a small-town Main Street has profound meaning within the American culture that has prevailed for the past two centuries. Historically, Main Street serves as the beating heart of a community, a place where economic, social, cultural, and civic activities are centered (Francaviglia, 1996; Main Street America, n.d.). Since the beginning of the 19th century, many factors have led to the decline of Main Streets, and despite a variety of efforts from different stakeholders, that decline has only intensified in recent decades (Isenberg, 2008; Orvell, 2014 Howard, 2015). In 1980, after a three-year project conducted by the National …


Smart Transportation In Small- And Medium-Sized Cities In Central California, Hongwei Dong May 2023

Smart Transportation In Small- And Medium-Sized Cities In Central California, Hongwei Dong

Mineta Transportation Institute

The research on smart transportation in the United States has centered on large metropolitan areas. The adoption of smart transportation technologies in small-and medium-sized cities outside of large metropolitan areas is less studied and understood. This study examined the adoption of smart transportation technologies in small-and medium-sized cities in Central California. The analysis was based on the online survey responses from 29 transportation officials and professionals who worked for 18 municipal government departments and six metropolitan planning organizations (MPOs) in Central California as well as in depth semi-structured interviews with seven of them. The study showed that smart transportation in …


Electric Vehicle Routing Problem – Models And Algorithms, Hesamoddin Tahami May 2023

Electric Vehicle Routing Problem – Models And Algorithms, Hesamoddin Tahami

Engineering Management & Systems Engineering Theses & Dissertations

The transportation sector is a major greenhouse gas emitter that is heavily regulated to reduce its dependence on oil. These regulations along with the growing customer awareness of global warming have led to the investigation of new transportation problems that consider using eco-friendly vehicle fleets. Promising alternatives to traditional fleets include alternative fuel vehicles (AFVs) and electric vehicles (EVs). These twenty-first-century vehicles offer an appealing advantage of consistently reducing their environmental impact, but due to the current technology, they exhibit bothersome limitations. The short driving range along with limited charging infrastructure may consequently cause issues related to range anxiety, i.e., …


Paved With Good Intentions? A Geopolitical Analysis Of The Belt And Road Initiative In Central And Eastern Europe, Vincent Zhang Apr 2023

Paved With Good Intentions? A Geopolitical Analysis Of The Belt And Road Initiative In Central And Eastern Europe, Vincent Zhang

Independent Study Project (ISP) Collection

The objective of this analysis is to reveal the geopolitical and geoeconomic significance of the Belt and Road Initiative (BRI) to the region of Central and Eastern Europe (CEE). Launched in 2013 as a proposal for increased economic interconnectivity between China and Kazakhstan, the BRI has since grown to encompass hundreds of countries across Asia, Africa, and Europe. The region of CEE is of note as it is coterminous with important regional groupings like the 14 + 1 Cooperative Framework between China & CEE and a point of overlapping interests from actors like the European Union (EU), North Atlantic Treaty …


Using Thermal Remote Sensing To Quantify Impact Of Traffic On Urban Heat Islands During Covid, My-Thu Tran, Bo Yang Apr 2023

Using Thermal Remote Sensing To Quantify Impact Of Traffic On Urban Heat Islands During Covid, My-Thu Tran, Bo Yang

Mineta Transportation Institute

A three-month lockdown in the U.S. at the beginning of the COVID-19 outbreak in 2020 greatly reduced the traffic volume in many cities, especially large metropolitan areas such as the San Francisco Bay Area. This research explores the impact of transportation on climate change by using remote sensing technology and statistical analysis during the COVID-19 lockdown. Using thermal satellite data, this research measures the intensity of the urban heat island, the main driver for climate change during the urbanization process. The research team acquired morning and afternoon MODIS data in the same periods in 2019 before the pandemic and 2020 …


Modeling And Evaluating Alternatives To Enhance Access To An Airport And Meet Future Expansion Needs, Srinivas S. Pulugurtha, Abimbola Ogungbire, Chirag Akbari Apr 2023

Modeling And Evaluating Alternatives To Enhance Access To An Airport And Meet Future Expansion Needs, Srinivas S. Pulugurtha, Abimbola Ogungbire, Chirag Akbari

Mineta Transportation Institute

The continued growth of air travel calls for the incessant construction effort at many airports and their surroundings. Thus, there is a need to determine how airports can better manage existing infrastructure to accommodate this growth. This study, therefore, focuses on (1) investigating how changes in transportation infrastructure have affected travel time reliability (TTR) of the surrounding road network within the airport vicinity over time, and, (2) exploring selected unconventional intersection designs and proposing new inbound/outbound access routes from the nearby major roads to the airport. The efficiency of road networks that surrounds large airports is discussed using Charlotte Douglas …


Investigating The Detriment Of Development Assistance: A Geopolitical Analysis Of Sino-Djibouti Relations Through The Lens Of China’S Belt And Road Initiative, Elizabeth Elenwo-Roger Apr 2023

Investigating The Detriment Of Development Assistance: A Geopolitical Analysis Of Sino-Djibouti Relations Through The Lens Of China’S Belt And Road Initiative, Elizabeth Elenwo-Roger

Independent Study Project (ISP) Collection

This research paper will evaluate Africa’s past with debt accumulation, focusing on the role of the Washington Consensus spearheaded by the Bretton Woods Institutions in its failed attempts to relieve the continent’s debt distresses and further aggravate Africa’s already fractured relationship with the West. It will highlight the goals of the Belt and Road Initiative, assessing China’s South-South cooperation approach to its relations with Djibouti and the Horn of Africa. Specifically, it will investigate claims of China engaging in debt-trap diplomacy and the extent to which this term infringes upon the agency of African leaders. The general research question investigates …


Planning For Pedestrians And Bicyclists During Construction Projects, John Habermann, P.E. Mar 2023

Planning For Pedestrians And Bicyclists During Construction Projects, John Habermann, P.E.

Purdue Road School

This session will explore how the Texas Department of Transportation Waco District addressed pedestrian/bicyclist safety and mobility during a multi-year construction project along I-35. This presentation will demonstrate the value of online tools, field implementations, and data collection. Attendees will learn the value of assembling a stakeholder steering committee; counting pedestrian and bicyclists before, during, and after construction; effectively using pavement clings; and using a webpage dedicated to pedestrian/bicyclist updates.


See A Sign? Make A Call, John Habermann, P.E. Mar 2023

See A Sign? Make A Call, John Habermann, P.E.

Purdue Road School

DOT staff and technology resources have the proven potential to help combat human trafficking if DOT employees know the indicators of human trafficking and how to cooperate with requests from agencies for information that can be derived from DOT assets. The Texas A&M Transportation Institute, NCHRP, and the Heart of Texas Human Trafficking Coalition will discuss the intersection of human trafficking with the transportation sector. Attendees will also learn the main components of human trafficking, the basic signs of human trafficking on DOT facilities, and resources to use in their own states.


Evaluating Automated Truck Platoon (Atp) Deployment For The Los Angeles–Inland Empire Trade Corridor Enhancement, Shailesh Chandra, Aastha Chaudhary, Prakhar Srivastava, Jose Torres-Aguilera Mar 2023

Evaluating Automated Truck Platoon (Atp) Deployment For The Los Angeles–Inland Empire Trade Corridor Enhancement, Shailesh Chandra, Aastha Chaudhary, Prakhar Srivastava, Jose Torres-Aguilera

Mineta Transportation Institute

The California Freight Mobility Plan 2020 lists the Los Angeles-Inland Empire trade corridor region as a prominent industrial hub experiencing an increase in freight flows. The California Freight Mobility Plan also regards automated truck platoon (ATP) as an emerging opportunity to minimize congestion on the trade corridor routes. Percentage change in accessibility from 2022 (“without” ATP) to 2040 (“with” ATP) is calculated for the eighteen industry sectors of the Los Angeles-Inland Empire trade corridor. The application of the accessibility formulation was carried out with data on travel time from I-710 and I-10 within Los Angeles County. The findings suggest that …


Designing And Evaluating A Smartphone App To Increase Underserved Communities’ Data Representation In Transportation Policy And Planning, Courtney Cronley, Anna O'Dell, Noelle Fields, Stephen P. Mattingly, Nicole Iroz-Elardo, M. Christine Highfill, Rebecca Cole, Mary Kris Stringfellow Mar 2023

Designing And Evaluating A Smartphone App To Increase Underserved Communities’ Data Representation In Transportation Policy And Planning, Courtney Cronley, Anna O'Dell, Noelle Fields, Stephen P. Mattingly, Nicole Iroz-Elardo, M. Christine Highfill, Rebecca Cole, Mary Kris Stringfellow

School of Social Work Faculty Publications

The current global focus on transportation equity, as well as a move towards smart mobility, highlights the need for more representative transportation data to inform transportation planning. In this case study, an interdisciplinary research team describes the process of refining and evaluating the utility of a transportation daily diary mobile-phone-based app. The process is framed through transportation equity and diverse key stakeholder engagement. The team custom-designed the app, MyAmble, to capture successful transportation behaviors, as well as latent demand, defined as travel not taken but desired, among underserved populations. Stakeholder focus groups with subject matter expert (n = …


Dlr Covid-19 Mobility Review (Phase 2a): Report On Cmr Economic Development & Business Community Feedback, Sarah Rock Dr., Robert Bradshaw Dr., David O'Connor, Odran Reid Feb 2023

Dlr Covid-19 Mobility Review (Phase 2a): Report On Cmr Economic Development & Business Community Feedback, Sarah Rock Dr., Robert Bradshaw Dr., David O'Connor, Odran Reid

Reports

This research reports on the findings from an area focused economic development and business community focused study of the Costal Mobility Route (CMR), which is intended to complement and extend research previously conducted in Phase 1 of Dún Laoghaire-Rathdown County Council’s (DLR’s) ‘Covid-19 Mobility & Public Realm Works’ project. This study is based on participant interviews, and is limited to businesses located directly along the CMR, as well as a number of business groups representing a wider area and a Local Enterprise Office.

While one company reported a significant decline in revenue that they attribute to the CMR, the remainder …


Evaluation, Comparison, And Improvement Recommendations For Caltrans Financial Programming Processes And Tools, Wenbin Wei, Nigel Blampied, Raajmaathangi Sreevijay Feb 2023

Evaluation, Comparison, And Improvement Recommendations For Caltrans Financial Programming Processes And Tools, Wenbin Wei, Nigel Blampied, Raajmaathangi Sreevijay

Mineta Transportation Institute

The California Transportation Improvement Program System (CTIPS) is the main tool used by Caltrans’ Division of Financial Programming to support the business of transportation programming. It is a multi-agency joint-use project programming database system applied to develop and manage various state and federal transportation programming documents. The goal of this project is to evaluate CTIPS and explore various new options that will maintain the current functionality of CTIPS, meet legislative guidelines for ADA compliance, ensure security of the system, and have sufficient scalability and capabilities for integration with other systems in the future. The research is based on the review …


Evaluation Of Nanoclay Additives For Improving Resistance To Moisture Damage In Hot Mix Asphalt (Hma), Amro El Badawy, Ashraf Rahim Jan 2023

Evaluation Of Nanoclay Additives For Improving Resistance To Moisture Damage In Hot Mix Asphalt (Hma), Amro El Badawy, Ashraf Rahim

Mineta Transportation Institute

Transportation has an enormous impact on the U.S. economy and on the lives of all Americans. Many modes of transportation rely on pavement, but pavement conditions deteriorate over time because of the combined effects of traffic and climate. Exposure to moisture often causes premature failure of asphalt pavements as it reduces the stiffness of the asphalt and enables stripping of the asphalt from the aggregate. This research evaluates the effectiveness of clay nanomaterials (i.e., nanoclays) in improving the resistance of hot mix asphalt (HMA) to moisture damage and compares the enhancement results to anti-stripping additives commonly used in pavement construction. …


The Rhetorical Art Of Risk Assessment: Lessons From Risk Management In Rural And Tribal Communities, John L. Velat Jan 2023

The Rhetorical Art Of Risk Assessment: Lessons From Risk Management In Rural And Tribal Communities, John L. Velat

Dissertations, Master's Theses and Master's Reports

Risk assessment, mitigation, and communication rely on data from multiple sources to form a complete understanding of hazards and how to manage them. Experts can use these data to make informed decisions about the nature and extent of risks and inform the public to protect health, the environment, and economic welfare. However, in an effort to objectively make decisions, technical experts and policymakers increasingly rely on quantitative data as the most important determiner of risk, which can alienate the public, limit risk understanding, and delay or miss obvious signals of impending catastrophe. I examine several cases based on my experiences …


Are Ride-Hailing Services Safer Than Taxis? A Multivariate Spatial Approach With Accomodation Of Exposure Uncertainty, Guocong Zhai, Kun Xie, Hong Yang, Di Yang Jan 2023

Are Ride-Hailing Services Safer Than Taxis? A Multivariate Spatial Approach With Accomodation Of Exposure Uncertainty, Guocong Zhai, Kun Xie, Hong Yang, Di Yang

Civil & Environmental Engineering Faculty Publications

Despite many research efforts on ride-hailing services and taxis, limited studies have compared the safety performance of the two modes. A major challenge is the need for reliable mode-specific exposure data to model their safety outcomes. Moreover, crash frequencies of the two modes by injury severities tend to be spatially and inherently correlated. To fully address these issues, this study proposes a novel multivariate conditional autoregressive model considering measurement errors in mode-specific exposures (MVCARME). More specially, a classical measurement error structure is used to accommodate the uncertainty of mode-specific exposures estimated, and a multivariate spatial specification is adopted to capture …