Civil and Environmental Engineering Commons^™

Barriers And Drivers To Bus Electrification: The Transit Agency's Perspective, Aleks C. Paskett

All Graduate Theses and Dissertations, Fall 2023 to Present

Battery-electric buses (BEBs) have become increasingly common in recent years, as transit agencies around the world seek to reduce their carbon emissions. Although many agencies and governments have set ambitious climate goals pushing for increased adoption of BEBs, some agencies face difficulty transitioning their fleets to this technology. This study seeks to understand the challenges faced by these agencies, as well as their motivations for adopting BEBs. Researchers conducted a series of interviewers with twelve transit leaders representing ten transit agencies who were leading BEB adoption programs, asking questions about their experiences trying to implement this technology. The interviewees stated …

Investigating The Conversion Of A Signalized Intersection To A Turbo Roundabout, Vyshnavi P. Shetty

Master's Theses

Turbo roundabouts are multilane roundabouts that utilize a spiral design with raised lane dividers to guide traffic flow effectively. While they have seen widespread use in Europe, California is the second state in the US (after Florida) to have installed a turbo roundabout. Turbo roundabouts separate the ingress and circulating lanes. The concept was first proposed and implemented in the Netherlands to address safety concerns and improve traffic flow efficiency on conventional multilane roundabouts.

This research evaluates the first-ever turbo roundabout in California and compares its safety and operational performance with the previously existing 4-legged signalized intersection. The research team …

Transportation Policies, Programs And History, Ivonne Audirac, Amber B. Raley, Jenifer Reiner, Soheil Sharifi-Asl

Mavs Open Press Open Educational Resources - Archive

Transportation Policies, Programs and History is a text intended for advanced undergraduate and beginning graduate students in urban and transportation planning. Contents by chapter include:

1. Brief history of U.S. transportation policy and traffic congestion: A persistent transportation planning issue.
2. Transportation planning and modeling.
3. Transportation programming and evaluation.
4. Equity in transportation planning
5. Mobility modes.
6. Transportation, accessibility, and the built environment.
7. Transit and transit-oriented development.
8. Transportation and new technologies.
9. Sustainable transportation.
10. Transportation in the Global South.

This textbook is part of a six-volume series produced under the grant OERTransport: Enabling Transportation Planning Professional Advancement awarded to the University of Texas-Arlington (UTA) …

Integrated Sustainability Analysis Of A Shared Micro-Mobility System In University Campus: Life-Cycle Assessment And User Impact Study Of Electric Scooters, Md Afif Rahman Chowdhury

LSU Master's Theses

The objective of this study is to evaluate the environmental, economic, and social impacts of implementing e-scooter technology on the LSU campus. The study is structured into three main parts: (1) an environmental life-cycle assessment of e-scooters, (2) a comparative environmental and economic impact assessment of e-scooters, cars, and campus shuttle buses, and (3) a comprehensive survey of e-scooter users to assess their characteristics, satisfaction levels, and comfort while using e-scooters on the LSU campus.

To achieve the objectives of the study, a life-cycle assessment (LCA) was conducted to assess the environmental sustainability of e-scooters, encompassing all stages from raw …

Next Generation Permeable Pavement For Enhanced Durability And Functionality, S M Tanvir

LSU Master's Theses

Porous Asphalt Concrete (PAC), also known as Open-Graded Friction Course (OGFC), is known for its high permeability, which provides benefits such as enhanced rainwater drainage, improved skid resistance, and reduced hydroplaning risks. These characteristics are due to its high air void content, allowing water to flow through the pavement and reducing splash, spray, and noise compared to conventional asphalt mixes. However, this high air void content also contributes to durability concerns, such as raveling, stripping, and clogging, which can reduce service life and increase costs, making OGFC more expensive than conventional asphalt mixtures.

This research focuses on identifying the failure …

Measuring Integrated Accessibility For Sustainable Mobility: A Fuzzy Set Approach Case Study, Behnam Tahmasbi, Poria Hajian, Farzaneh Tahmasbi, Qian He

School of Earth & Environment Departmental Research

Sustainable transportation is vital to climate justice and social equity. Despite the efforts to achieve sustainability, there is still a lack of adequate measurement that integrates land use and transportation systems, which can be barriers to planning implementation. With methodological improvements in fuzzy theory application, this study develops an integrated index to measure the sustainability of multimodal accessibility. We do so by defining a fuzziness degree based on the different trip purposes and modes of transportation with a case study in Isfahan, Iran. Sustainable accessibility indicators were developed for walking, biking, and public transportation to represent the performance of each …

Unlocking Telecommuting Patterns Before, During, And After The Covid-19 Pandemic: An Explainable Ai-Driven Study, Adedolapo Ogungbire, Suman Kumar Mitra

Civil Engineering Faculty Publications and Presentations

The COVID-19 pandemic has instigated a global paradigm shift in employment practices, precipitating a widespread transition to telework. While past events had no long-lasting effect on the continued working conditions of the population, it is unclear what a prolonged need for telecommuting on such a nationwide scale would continue to have on the working population. This study uses an explainable artificial intelligence approach to investigate the changes in those telecommuting across three periods: i) pre-pandemic, ii) pandemic, and iii) post-pandemic periods. Machine learning methods, including decision trees, random forest, extreme gradient boost, naïve Bayes, and artificial neural networks, were developed …

Economic Contribution Of Kentucky Airports, P. Gayle Marks, Bethany Paris, Bryan Gibson

Kentucky Transportation Center Research Report

Airports generate economic impacts that are felt well beyond their physical boundaries by supporting commerce, tourism, and the provision of essential services. To understand the economic contributions of airports throughout Kentucky, researchers collected data from general aviation (GA) airports and commercial service (CS) airports across the state on operational statistics, levels of employment, and usage patterns in calendar year 2022. IMPLAN^® econometric models were developed to estimate the economic contributions of the state’s airports. These models show that in 2022 Kentucky’s airports contributed $23.7 billion in total economic output, which equals 9.1 percent of its gross domestic product ($261.5 …

Improving Transportation Resiliency, Ben Blandford, Erin Lammers-Staats, Emma Gregory

Kentucky Transportation Center Research Report

Transportation agencies are increasingly more challenged by the effects of extreme weather and national hazards on transportation assets.  Severe weather events in Kentucky have become more frequent and more costly. These extreme events damage transportation assets, increase maintenance costs and strain transportation budgets. Climate models predict changing conditions to occur over the next century that differ from historical data. In Kentucky, models predict a warmer and wetter environment. The goal of this research is to help KYTC plan for extreme weather and natural hazards events, as well as absorb, recover from, and adapt to the resulting damage.  Researchers determined where …

Accelerated Bridge Construction (Abc) Decision Tool, Phil Barutha, Marc Maguire, Elio Saldana, Fray F. Pozo-Lora

Nebraska Department of Transportation: Research Reports

This report investigates the creation and assessment of a decision-making tool developed to aid the Nebraska Department of Transportation (NDOT) in determining the suitability of the Accelerated Bridge Construction (ABC) method for bridge replacement projects. The tool utilizes the Analytic Hierarchy Process (AHP) to integrate different criteria, including Average Daily Traffic (ADT), Average Daily Truck Traffic (ADTT), detour time, railroad impact, economy of scale, and the use of typical details, which were found to be paramount in the decision-making process across the state. A sensitivity analysis was conducted to evaluate the tool’s performance and identify the most significant factors influencing …

Effect Of Antioxidant Additives And Recycling Agents On Performance Of Asphalt Binders And Mixtures – Phase Ii, Nitish R. Bastola, Muhammad Ahmad, Mahdieh Khedmati, Jamilla Teixeira, Hamzeh Haghshenas

Nebraska Department of Transportation: Research Reports

The use of reclaimed asphalt pavement (RAP) in combination with recycling agents (RAs) (i.e., rejuvenators or softening agents) has gained significant attention from the pavement industry as a sustainable pavement solution, reducing the carbon footprint of manufactured products through the conservation of energy and reduction on the use of raw materials. Current research has found that RAs can improve RAP recycled asphalt mixture’s cracking resistance, while being capable of maintaining their rutting resistance. However, there are some concerns about the effect of RAs on the moisture damage resistance and the long-term performance (aging) of these additives. The current need is …

Green Cities And Transportation, Ariadna Reyes-Sanchez, Soheil Sharifi-Asl, Ladan Mozaffarian

Mavs Open Press Open Educational Resources - Archive

Green Cities and Transportation examines the significance of sustainable transportation projects for mitigating greenhouse gas emissions while supporting transportation equity for vulnerable commuters. The book examines insightful case studies from around the world that can serve as a reference for sustainable transportation initiatives in the U.S. It is organized into three sections: 1) Sustainability, Transportation Equity, and Planning, 2) Case Studies and Lessons from the North and South, and 3) Greenhouse Gas Emissions, Cities, and Mobility.

Transportation Land Use Modeling And Policy, Qisheng Pan, Soheil Sharifi-Asl

Mavs Open Press Open Educational Resources - Archive

Transportation Land Use Modeling and Policy provides a comprehensive introduction to land use and transportation models, offering a detailed exploration of integrated modeling approaches through case studies and real-world examples. It begins with an overview of current transportation planning issues and moves into several chapters dedicated to integrated land-use and transportation models, including Land Suitability, Lowry-type models, and more recent approaches such as MEPLAN and PECAS. The book also examines traditional travel demand modeling (TDM), giving readers a solid foundation in the subject.

Treatment Methods Of Unstable Expansive Soil Slope Excavation In Overlying Rock Layer In Alpine Region, Shi Xiaobo, Cui Guangyan, Mou Chao, Wen Ye, Xie Feng, Fu Xiaoyang

Journal of China & Foreign Highway

To deeply study the treatment method for instability of highway cutting slope under the condition of expansive soil overlying rock layer in an alpine region，the comprehensive treatment method of unstable slope under this bad geology was put forward based on the unstable slope project of Zhangbei‒Shangyi Expressway.The governance protection structure consisted of a rigid protection system，drainage system，thermal insulation system，flexible protection system，and waterproof system.The rigid protection system was an anti-slide pile setting at the height of 1/3 of the first grade slope，of which parameters were calculated by cutting the slope of the rock layer in the unstable area to reduce the …

Treatment And Measurement Of Water Inrush During Highway Tunnel Construction, Wang C Haojie, Feng Zhihua, Fan Haobo

Journal of China & Foreign Highway

As a special geological condition of highway tunnels，water inrush will cause difficulties in engineering construction technology and management.Unnecessary disputes and management difficulties will emerge when different construction units hold different views about the treatment measures of water inrush，which leads to distributed provisions in the specification and a long treatment period.In view of key problems about the water inrush during highway tunnel construction，including water inrush treatment concept，investigation and estimation，measurement and pricing，and on-site confirmation，this paper systematically sorted out the current regulations and other guiding documents and investigated the treatment methods of tunnel water inrush and reverse slope pumping in China ’s highway …

Review Of Evaluation Methods For Mixing Workability Of Asphalt Mixture, Dong Fuqiang, Zu Yuanzhe, Yu Xin, Chen Bei, Liu Lin

Journal of China & Foreign Highway

To clarify the evaluation methods an d research status of mixing workability of asphalt mixture， by consulting relevant research literature in China and abroad and analyzing different evaluation methods，indexes，and research findings of the workability of asphalt mixture，the applicability and evaluation effects of different workability evaluation methods were systematically summarized，and the comparative analysis and comprehensive review were made on the main influencing factors of the mixing workability.The results show that in most evaluation methods for the mixing workability of asphalt mixture，corresponding indexes are constructed to quantitatively evaluate the workability by quantifying the resistance or energy consumption in the mixing process.Besides，in some …

Research Review Of Biomass Ash As Concrete Admixture, Ma Bicong, Liang Jian, Weng Yiling

Journal of China & Foreign Highway

In order to provide a comprehensive overview of research progress in the use of biomass ash as concrete admixture，the physical and chemical properties，mechanism of action，factors affecting the production process of biomass ash，and the effects of biomass ash incorporation on the working properties，mechanical properties，and durability of concrete were studied.The results show that biomass ash has a smaller density and a larger specific surface area than traditional mineral admixture，and the total amount of active components，namely SiO2 + Al2O3 + Fe2O3 （SAF） in most biomass ashes exceeds the requirements of class F volcanic ash （≥70%）.Incorporating biomass ash can effectively improve the mechanical properties …

Compaction Characteristics Of Granular Material And Its Structural Mechanical Behavior Considering Orthotropy, Huang You, Zhang Yunbao, Liu Zhaohui, Pan Yu, Liu Zebin, Fang Ronghai

Journal of China & Foreign Highway

The orthotropy of granular materials is closely related to the compaction process and has a significant impact on the mechanical behavior of pavement structures.In this study，in order to study the effect of the compaction process on the orthotropy of granular materials，different compaction methods and compaction energies were employed to compact granular materials for pavement into specimens，and improved dynamic resilient mechanical tests were conducted.Orthotropic coefficients （α2） of typical granular materials were obtained，and the finite element method was used to conduct mechanical analysis of asphalt pavement structures considering the orthotropy of granular materials.The results show that the dry density of specimens by …

Effect Of Basalt Fiber On Strength Of Cement‑Stabilized Macadam Base, Shu Hongbo, Tang Zhengguang, Zhang Yanhong, Bu Xilian, Liang Dong

Journal of China & Foreign Highway

To study the performance of basalt fiber in improving the poor angularity of the crushed cobble base，based on the orthogonal test，this paper determined that the optimal dosage of basalt fiber in the cement-stabilized crushed cobble was 1 kg/m3 （15 mm） + 2 kg/m3 （25 mm）.Besides，unconfined compressive strength and splitting strength tests were carried out on mixtures under three working conditions including the cement-stabilized crushed cobble，cement-stabilized crushed cobble with the optimal dosage of basalt fiber，and cement-stabilized macadam （limestone machine-crushed stone ）.The results show that influenced by the aggregate angularity，the strength of the cement-stabilized macadam （limestone machine-crushed stone ） mixture is better …

Design And Simulation Of Anti‑Collision System On Independent Pile With External Composite, Liao Yuanyuan, Liu Yu, Zhu Lu, Fang Hai, Zhang Jinrui, Han Juan

Journal of China & Foreign Highway

The precise calculation of the ship-bridge collision force is necessary for the assessment of the structural safety of the bridge and the design of an effective anti-collision system.Taking the ship-bridge issue in Furong Bridge in Xiangtan City，this paper compared the collision forces from different angles and in different locations calculated through the finite element software Ansys/LS-DYNA with the results calculated through the empirical formula，thereby determining the fortification collision forces of the bridge piers.Based on the weak anti-collision ability of the bridge double-limb thin-walled pier，the paper designed and implemented a new anti-collision system combined with composite and concrete-filled steel independent piles.The …

Intelligent Recognition Technology Of Highway Cracks Based On Semantic Segmentation, Gao Liang, Rao Faqiang, Yang Zhongmin, Dai Zongsheng, Sun Hao

Journal of China & Foreign Highway

Real-time detection and timely treatment of highway cracks are crucially fundamental for vehicle safety.Rapid identification and comparison of cracks is a new method for monitoring the development and changes of geological disasters especially when they induce cracks.Therefore，this study proposed an intelligent recognition method of highway cracks based on semantic segmentation，establishing a model with dataset，neural network，calculation parameters，and evaluation indicators to rapidly identify the cracks.The results show that，firstly，when the neural network Attention U-net built in this study semantically segments highway cracks，the binary cross loss function value and accuracy rate reach 0.008 7 and 0.998 4，respectively.Secondly，compared with traditional algorithms，the semantic segmentation method shows …

Lessons Learned From 60 Years Of Pavement Trials In Continental Climate Regions Of Canada And Future Perspective, Wang Di, Li Jingxiao, Ren Xueyuan, Zhang Fan, Yuan Dongdong

Journal of China & Foreign Highway

During the early 1960 s，Canadian road authorities began using stiffer asphalt to address the issue of early rutting in the wheel track zone of asphalt pavements，which was caused by the growing traffic volumes.Pavements constructed with stiffer asphalt commonly exhibit evenly spaced transverse cracks due to the significant internal stresses caused by low temperatures and the inadequate resistance of the asphalt to cracking under such conditions.Research conducted on asphalt pavements with cracks caused by low temperatures has verified the significant impact of asphalt ’s consistency，temperature sensitivity，phase uniformity，and durability.In order to tackle the difficulties presented by the utilization of modified asphalt in …

Method Of Solving Initial Construction Cable Force Of Completed Cable‑Stayed Bridge, Xu Yufeng, Chen Si, Xie Yunfei, Zhu Mengyang

Journal of China & Foreign Highway

To solve the initial construction cable forces of a completed cable-stayed bridge，a method that combines unstressed cable length and forward-iteration is proposed.Firstly，the unstressed length of each cable is calculated according to the completed bridge state.Then，the initial cable forces are obtained by using the unstressed cable length for the forward analysis.The initial construction cable forces are adjusted by difference iteration.Finally，the initial construction cable forces are fine-tuned according to the deformation of the pylon deformation to obtain the bridge completion state that satisfies the deviation requirements.The proposed method is employed in a cable-stayed bridge with a known completion state to calculate the …

Experimental Study On Influence Of Stress Ratio On Fatigue Life Of High Strength Steel Wire, Zeng Yi, Yan Donghuang, Xu Hongsheng, Yang Ying

Journal of China & Foreign Highway

To clarify the influence of stress ratio on the fatigue life of high strength steel wire and verify the applicability of the fracture mechanics model to evaluate the fatigue life of steel wire，based on the assumption of equating wire corrosion pits to notches，fatigue tests were carried out on steel wire samples with different prefabricated notch depths at different stress ratios，and a fatigue life empirical equation considering the stress ratio effect was established.The results show that the fatigue life of the steel wire samples is significantly influenced by the stress ratio，which decreases with the increase in the stress ratio.The increase in …

Influence Of High Temperature On Large Cantilever Construction Control Of Wide Extradosed Cable‑Stayed Bridge, Zhu Haojie, Zhang Xiedong, Li Yong, Lin Yuan, Wu Di

Journal of China & Foreign Highway

In order to investigate the influence of temperature gradient on the construction of wide extradosed cable-stayed bridges in the large cantilever construction stage at high temperatures，the solar radiation and thermal boundary conditions of wide equal-height box girder were theoretically calculated，and the thermal analysis finite element model of the wide equal-height box girder was established by Abaqus.The cross-section temperature of the box girder was measured by intelligent string sensors and an infrared thermometer.The temperature gradient and its distribution of wide equal-height box girder from sunrise to sunset on a certain day in summer were calculated.The finite element model of the construction …

Back‑Calculation Of Subgrade Modulus Based On Genetic Algorithm And Viscoelasticity Theory, Dai Fugui, Wang Xihui, Wu Yaguang, Li Hai

Journal of China & Foreign Highway

To improve the applicability of the PFWD detection method for the back-calculation of subgrade modulus，taking the subgrade splicing project of the west loop line in Nairobi as an example，this paper adopted 3D Kelvin viscoelasticity model and quasi-static response analysis to deduce the displacement function of viscoelastic subgrade under long-term fixed loads，and combined the principle of liner superposition of viscoelasticity with genetic algorithm to propose a new method based on multi-population genetic algorithm for the modulus back-calculation of viscoelastic subgrade.Among them，the corresponding program for back-calculation was written by Matlab.The comparison between theoretical derivation and field tests shows that the peak value …

Overall Design Concept Of Municipal Reconstruction Of Cross‑City Expressway, Fu Yuankun, Zhang Yu

Journal of China & Foreign Highway

The municipal reconstruction of the cross-city expressway is of great significance in enlarging the urban framework，refining the spatial pattern，and promoting the integrated development of clusters.However，China’s expressways seldom undergo municipal reconstruction，with less synergy formed with cities.Therefore，taking one case described above in Hebei Province as an example，this article proposed the overall design concept of integrating with the city from urban space，road networks，municipal facilities，urban ecology，cultural landscape，and other perspectives after analyzing problems in urban space，traffic，industry，landscape and urban quality in existing cross-city expressways. In addition，this paper studied and optimized the municipal reconstruction plan.Holding a theme of “municipalization ”，the plan eliminated the fragmentation of urban space …

Progress And Prospects Of Road Engineering Disease Treatment Technology In Permafrost Regions, Gao Feng, Zeng Xianzhang, Zhong Wenhua, Huang Shengyong, Zhang Junhui

Journal of China & Foreign Highway

Freeze-thaw disasters are key issues affecting the service performance and operational safety of road projects in permafrost regions.Under the combined influence of warming and humidification of the permafrost environment and engineering thermal effects，the degradation of permafrost is accelerating，exacerbating the risk of road freeze-thaw diseases.Roads in these regions are more frequently maintained and repaired to ensure service performance，with a service life lower than designed.Therefore，deepening the understanding of the disaster mechanism of road geotechnical structures and strengthening the study on engineering disease treatment technology are of great significance in promoting the construction and maintenance of high-quality and high-grade highways in frozen regions.This …

Model Test On Soil Deformation Mechanism And Damage Mode Caused By Mud Leakage From Drilled Piles In Karst Area, Jiang Mingying, Chen E ’Mei, Liu Yongcheng, Zhu Yadong, Jiang Wenkui, Xie Ruiting

Journal of China & Foreign Highway

Pile holes are often drilled through cavities in karst areas，which induces mud leakage and causes hole wall instability，ground collapse，or equipment trapping and hinders smooth construction.It is important to know the collapse mechanism of boreholes due to mud leakage，so as to optimize and determine the construction process of pile holes.In this paper，indoor model tests were used to study the deformation mechanism and damage mode of soil caused by drilling through cavities and mud leakage in pile holes under the conditions of upper clay and lower sandy soil in the karst area，so as to provide an experimental basis for the decision of …

Deformation Measurement And Safety Warning Of Highway Bridges Based On Machine Vision, Su Ziyue, Du Wenkang, Lei Dong

Journal of China & Foreign Highway

The structural safety of highway bridges plays a crucial role in traffic safety operations and regional economic development.Due to the rapid increase and complex changes in traffic loads，the demand for real-time monitoring of bridge ’s structural deformation and safety conditions has been increasingly prominent.However，the structural health monitoring system，dominated by contact sensors，has limitations such as difficult installation and construction，complicated maintenance and replacement，and the need to interrupt traffic.To this end，a non-contact deformation measurement system based on machine vision was proposed.Template matching and feature point recognition methods were utilized to achieve recognition of structural surface markings and displacement extraction of key positions.The accuracy …