Engineering Commons^™

Remediating Soil For Successful Vegetation Establishment Along Nebraska Highways, Shad Mills, Martha Mamo, Walt Schacht, Humberto Blanco-Canqui

Nebraska Department of Transportation: Research Reports

Vegetation along roadsides is important to prevent soil erosion, provide habitat, and filter water running off the road. Vegetation close to the pavement along highways in Nebraska does not readily establish and persist. It is thought that the sodium and bulk density are the driving factors behind the lack of vegetation. After a construction project the shoulder is seeded into the compacted soil, and during winter salts can accumulate in the soil because of deicing agents being used. The purpose of our study was to determine if the sodium and bulk density are the driving factors of the vegetation cover. …

Establishment Of Wildflower Islands To Enhance Roadside Health And Aesthetics, Walter Schacht, Judy Wu-Smart

Nebraska Department of Transportation: Research Reports

Wildflowers are crucial in the ecological function of the low-input roadside plant communities in terms of water andnutrient cycling, nutrient inputs such as nitrogen, total plant canopy cover, stand longevity, and provision of habitat for numerous small animals. Further, wildflowers provide critical foraging and nesting resources for birds, insects, and other wildlife. Unfortunately, habitat loss from agricultural and urban development has led to rapid population declines in wild bees and other pollinators across the US, thereby jeopardizing not only food production but also the sustainability of our natural landscapes (Kearns & Inouye, 1997). One way to mitigate wild bee decline …

Evaluation Of Reducing Cement Content In Ndor Class R Combined Aggregate Gradations, Miras Mamirov, Jiong Hu, Yong-Rak Kim

Nebraska Department of Transportation: Research Reports

The main objective of this research project was to achieve a cement reduction on Nebraska slip-form pavement concrete through aggregate particle packing optimization. A literature review was conducted to examine different aggregate optimization tools, quality control tests, and historical data of Nebraska Department of Transportation (NDOT) pavement mixtures. It was found that the Modified Toufar Model has good potential in optimizing particle packing and predicting packing degrees. The combined aggregate void content test was found to be useful to experimentally justify optimized aggregate gradations. The Box Test with a modified index and image analysis tool for surface void estimation was …

The Potential For Using Loyalty Rewards And Incentives Programs To Encourage Transit Ridership And Regional Transportation And Land Use Integration, Christopher E. Ferrell

Mineta Transportation Institute Publications

Transit smart cards can be used as a tool for increasing transit ridership, increasing retail sales in transit-oriented developments (TODs) and eventually, increasing opportunities for retail development in TODs. Instead of providing separate loyalty rewards for each store, or chain of stores, such cards would provide loyalty rewards—in several possible forms, including free transit ride credits, cash rewards, retail purchase discounts, sweepstakes rewards—to all transit riders who patronize TOD retail businesses. Additional rewards could also be given to transit riders who live, work, and shop in TODs, and even to riders who take transit for specific shopping trips in TODs. …

An Application Of Bayesian Multilevel Model To Evaluate Variations In Stochastic And Dynamic Transition Of Traffic Conditions, Emmanuel Kidando, Ren Moses, Thobias Sando, Eren Erman Ozguven

Civil and Environmental Engineering Faculty Publications

© 2019, The Author(s). This study seeks to investigate the variations associated with lane lateral locations and days of the week in the stochastic and dynamic transition of traffic regimes (DTTR). In the proposed analysis, hierarchical regression models fitted using Bayesian frameworks were used to calibrate the transition probabilities that describe the DTTR. Datasets of two sites on a freeway facility located in Jacksonville, Florida, were selected for the analysis. The traffic speed thresholds to define traffic regimes were estimated using the Gaussian mixture model (GMM). The GMM revealed that two and three regimes were adequate mixture components for estimating …

Development Of High-Performance Rapid Patching Materials For Pavement Repair, Gholami Shayan, Jiong Hu, Yong-Rak Kim

Nebraska Department of Transportation: Research Reports

Concrete pavements exhibiting severe distresses which require patching are commonly observed in the concrete pavement in Nebraska. Due to the requirements of opening pavement to traffic after placing the rapid patching materials, it is essential for that concrete to achieve high early strength. To ensure this, a high cement content and chloride-based accelerators are currently used in the Nebraska Department of Transportation (NDOT) Portland cement-based rapid-patching materials. Besides its associated high cost, high cement content tends to result in a less stable mix with high shrinkage, high heat of hydration, and high cracking potential. In addition, using chloride-based accelerators has …

Standard Design For Nebraska County Bridges, Chungwook Sim, Jiong Hu, Maher K. Tadros, Alexander Bleyhl, David Gee

Nebraska Department of Transportation: Research Reports

Many county-owned bridges in Nebraska need replacement due to their structural deficiency. Most of the bridges needing replacement are in the 40 to 60 ft range. This span range lacks a standard design that fits Nebraska county practices in terms of speed and simplicity of construction. The current systems being used are (a) Precast 1 by 2 ft planks which can span up to 30 ft, (b) Cast-in-place slab bridges which can span up to 50 ft but require extensive field formwork, concrete placing, and curing, and are best when constructed in three-span units, and (c) Inverted tees which can …

Building Along The Railroad: Towns And Tourism In Michigan’S Eastern Upper Peninsula, Bridget Stoetzer

Honors Projects

The state of Michigan is not solely the lower portion or in other words the “mitten.” It is a combination of the lower and upper peninsula. The Upper Peninsula of Michigan (abbreviated the “UP”) is the upper portion of Michigan that is surrounded on three sides by three different Great Lakes: Lake Superior, Lake Michigan, and Lake Huron. It connects to the Lower Peninsula of Michigan by the Mackinac Bridge which crosses five miles across the Straits of Mackinac.

The counties of the Eastern Upper Peninsula are Alger, Chippewa, Luce, Mackinac, and Schoolcraft. They are marked by large stretches of …

Long-Term Performance Evaluation Of Nudeck In Kearney East Bypass, George Morcous, Marc Maguire

Nebraska Department of Transportation: Research Reports

The Kearney East Bypass bridge is the first project that implements the newly developed precast concrete deck system (known as 2nd generation NUDECK). The new system consists of full-depth full-width precast prestressed concrete deck panels that are 12 ft (3.66 m) long each. The panels have covered shear pockets at 4 ft (1.22 m) spacing on each girder line to host clustered shear connectors that are adjustable in height. Narrow unreinforced transverse joints are used to eliminate the need for deck overlay. Also, deck panels are post-tensioned in the longitudinal direction using a new post-tensioning system that eliminates the need …

Condition Assessment Of Bridge Decks With Asphalt Overlay, Sepehr Pashoutani, Jinying Zhu

Nebraska Department of Transportation: Research Reports

Ground penetrating RADAR (GPR) is a widely used nondestructive testing (NDT) method for bridge deck evaluation. However, the current GPR signal and data processing software and algorithms are not able to provide comprehensive information about bridge deck condition. Although the original objective of this research project was to develop GPR analysis algorithms for condition assessment of bridge decks with asphalt overlay, the scope of work has been expanded to concrete bridge decks with or without overlays.

In this study, the research team developed a complete GPR analysis procedure that includes the following components: 1) obtain zero-time for GPR reflection at …

Precast Concrete Deck-To-Girder Connection Using Uhpc, George Morcous, Mostafa Abo El-Khier

Nebraska Department of Transportation: Research Reports

The implementation of ultra-high-performance concrete (UHPC) in bridge construction has been growing rapidly in the last two decades due to its excellent mechanical properties, workability, and durability. This report presents a new UHPC connection between precast concrete deck panels and bridge girders that eliminates changes to the design and production of girder shear connectors commonly used in conventional cast-in-place concrete deck construction. In conventional construction, girder shear reinforcement or studs are extended into the cast-in-place concrete deck to transfer interface shear and create composite section. In the new connection, girder shear reinforcement or studs are kept underneath the deck panels, …

The Application Of Gray-Scale Level-Set Method In Segmentation Of Concrete Deck Delamination Using Infrared Images, Chongsheng Cheng, Zhigang Shen

Department of Construction Engineering and Management: Faculty Publications

Conventional nondestructive delamination detection of concrete pavements through thermography is often based on temperature contrasts between delaminated and sound areas. Non-uniform backgrounds caused by the environmental conditions are often challenging for contrast-based methods to robustly differentiate the delaminated areas from the sound areas. Instead of focusing on the temperature contrast, this study proposes a temperature gradient-based level set method (LSM) to detect boundaries for delamination segmentations. A modified edge indicator function is developed to represent the normalized temperature gradient of a thermal image. The experimental study was conducted to evaluate its applicability and stability for boundary detection in terms of …

Freeway Performance Measurement In A Connected Vehicle Environment Utilizing Traffic Disturbance Metrics, Leila Azizi

FIU Electronic Theses and Dissertations

The introduction of connected vehicles, connected and automated vehicles, and advanced infrastructure sensors will allow the collection of microscopic measures that can be used in combination with macroscopic measures for better estimation of traffic safety and mobility. This dissertation examines the use of microscopic measures in combination with the usually used macroscopic measures for traffic congestion evaluation, traffic state categorization, traffic flow breakdown prediction, and estimation of traffic safety. The considered macroscopic measures are the mean speed, traffic flow rate, and occupancy. The investigated microscopic measures for the stated purpose are: standard deviations of individual vehicle’s speeds, standard deviation of …

Moving From Walkability? Evaluation Traditional And Merging Data Sources For Evaluating Changes In Campus-Generated Greenhouse Gas Emissions, Troy Kawahara, Bo Liu, Anurag Pande, Calvin Thigpen, Carole Turley Voulgaris

Mineta Transportation Institute Publications

Universities are increasingly committing to reduce campus-generated greenhouse gas emissions, whether voluntarily or in response to a legal mandate. As an initial step to keeping these commitments, universities need an accounting of baseline greenhouse gas emissions levels and means of monitoring changes in campus-generated greenhouse gas emissions over time. Commute-generated greenhouse gas emissions from travel to and from campus by students and employees are among the most difficult to quantify. This report examines some of the challenges associated with estimating campus-generated greenhouse gas emissions and evaluates ways to address those challenges. The purpose of this study is to identify changes …

Critical Path For Project Development, Steven Douglas Kreis, Bryan Gibson, Jeff Jasper, Christopher W. Van Dyke, Candice Y. Wallace, Rachel Catchings, Sarah M. Mccormack

Kentucky Transportation Center Research Report

Overseeing the delivery of highway projects at the Kentucky Transportation Cabinet (KYTC) requires the successful coordination of activities and inputs from multiple external agencies and members of the agency’s Project Development team, who have varied disciplinary backgrounds. Despite the complexity of project delivery, the Cabinet presently does not estimate hours and project milestone dates until after it has selected a design consultant. Moving forward KYTC should explore requiring consultants to develop a critical path method (CPM) schedule. To facilitate this process, this report describes a methodology for producing CPMs for design contracts/projects based on procedures outlined in A Guide to …

Access Management Best Practices, Adam Kirk, Chris Van Dyke

Kentucky Transportation Center Research Report

Research has persistently demonstrated that adopting a systematic access management framework improves highway operations and bolsters safety. Many state transportation agencies have adopted formal access management programs to systematize the application of access management techniques, however, the Kentucky Transportation Cabinet (KYTC) been unable to institute such a program due to institutional, regulatory, and political constraints. Recognizing the benefits of judicious access management, the Cabinet asked researchers at the Kentucky Transportation Center (KTC) to identify access management best practices that are effective, can be easily implemented, and are compatible with existing statutes and regulations. After reviewing national-level and state-level guidance on …

Soil-Recycled Aggregate-Geopolymer Road Base/Subbase Mixtures: Steps Towards Sustainability, Mohammad Khattak, Daniel Odion

Data

Corresponding data set for Tran-SET Project No. 18GTLSU10. Abstract of the final report is stated below for reference:

"This study deals with the development of Soil-Geopolymer mixtures using flyash, alkali activator and recycled aggregates (RAG) including recycled concrete (RCA) and reclaimed asphalt (RAP) as an alternative to soil-cement for pavement base and subbase layers. Several mix constituents were varied such as flyash type and content, RCA and RAP content and ratio of sodium silicate and sodium hydroxide. Experiment design was established and mechanical and durability characteristics of Soil-RAG-Geopolymer mixtures were evaluated and then compared to the conventional soil-cement mixtures. The …

The Impact Of Hurricane Harvey On Pavement Structures In The South East Texas And South West Louisiana, Stefan Romanoschi

Data

Corresponding data set for Tran-SET Project No. 18PUTA02. Abstract of the final report is stated below for reference:

"This study developed a methodology to estimate the damage caused by flooding, such that caused by Hurricane Harvey, on a road or street network. The flooded street or pavement sections are identified using GIS flood maps with street GIS maps used for pavement management systems (PMS) by cities or state authorities. Then the damage caused by flooding directly through the increase moisture in foundation layers or indirectly due to the increase heavy traffic during the relief effort is estimated. An example Excel …

The Impact Of Hurricane Harvey On Pavement Structures In The South East Texas And South West Louisiana, Stefan Romanoschi

Publications

This study developed a methodology to estimate the damage caused by flooding, such that caused by Hurricane Harvey, on a road or street network. The flooded street or pavement sections are identified using GIS flood maps with street GIS maps used for pavement management systems (PMS) by cities or state authorities. Then the damage caused by flooding directly through the increase moisture in foundation layers or indirectly due to the increase heavy traffic during the relief effort is estimated. An example Excel macro was created to illustrate the estimation process. The methodology estimates the increase in rehabilitation costs since the …

Soil-Recycled Aggregate-Geopolymer Road Base/Subbase Mixtures: Steps Towards Sustainability, Mohammad Khattak, Daniel Odion

Publications

This study deals with the development of Soil-Geopolymer mixtures using flyash, alkali activator and recycled aggregates (RAG) including recycled concrete (RCA) and reclaimed asphalt (RAP) as an alternative to soil-cement for pavement base and subbase layers. Several mix constituents were varied such as flyash type and content, RCA and RAP content and ratio of sodium silicate and sodium hydroxide. Experiment design was established and mechanical and durability characteristics of Soil-RAG-Geopolymer mixtures were evaluated and then compared to the conventional soil-cement mixtures. The results of the testing showed that for the selected Soil-RAG-Geopolymer mixtures the strength, stiffness, permanent deformation, and durability …

Simulation Of The Impact Of Connected And Automated Vehicles At A Signalized Intersection, Hamad Bader Almobayedh, Deogratias Eustace, Philip Appiah-Kubi

Civil and Environmental Engineering and Engineering Mechanics Faculty Publications

Intersections are locations with higher likelihood of crash occurences and sources of traffic congestion as they act as bottlenecks compared with other parts of the roadway networks. Consequently, connected and automated vehicles (CAVs) can help to improve the efficiency of the roadways by reducing traffic congestion and traffic delays. Since CAVs are expected to take control from drivers (human control) in making many important decisions, thus they are expected to minimize driver (human) errors in driving tasks. Therefore, CAVs potential benefits of eliminating driver error include an increase in safety (crash reduction), smooth vehicle flow to reduce emissions, and reduce …

Incorporating Travel Time Reliability In Predicting The Likelihood Of Severe Crashes On Arterial Highways Using Non-Parametric Random-Effect Regression, Emmanuel Kidando, Ren Moses, Eren Erman Ozguven, Thobias Sando

Civil and Environmental Engineering Faculty Publications

© 2019 The Authors Travel time reliability (TTR) modeling has gain attention among researchers' due to its ability to represent road user satisfaction as well as providing a predictability of a trip travel time. Despite this significant effort, its impact on the severity of a crash is not well explored. This study analyzes the effect of TTR and other variables on the probability of the crash severity occurring on arterial roads. To address the unobserved heterogeneity problem, two random-effect regressions were applied; the Dirichlet random-effect (DRE) and the traditional random-effect (TRE) logistic regression. The difference between the two models is …

Strategic Implications For The United States Of The Belt And Road Initiative In Africa, Alec Monnie

Independent Study Project (ISP) Collection

The belt and road initiative is one of the most significant developments of the twenty-first century, which the United States will need to learn to adapt to. Much of the academic literature regarding the belt and road initiative mentions that Africa is a significant participant in this policy development, but fail to elaborate as to why that is, or what the implications for this are for the United States. This article expands upon the strategic significance of the African continent, and explains the implications thereof for the United States and China. This article argues that the belt and road initiative …

A Framework For Integrating Transportation Into Smart Cities, Susan Shaheen, Adam Cohen, Mark K. Dowd, Richard Davis

Mineta Transportation Institute Publications

In recent years, economic, environmental, and political forces have quickly given rise to “Smart Cities” -- an array of strategies that can transform transportation in cities. Using a multi-method approach to research and develop a framework for smart cities, this study provides a framework that can be employed to:

1. Understand what a smart city is and how to replicate smart city successes;
2. The role of pilot projects, metrics, and evaluations to test, implement, and replicate strategies; and
3. Understand the role of shared micromobility, big data, and other key issues impacting communities.

This research provides recommendations for policy and professional practice …

Predicting Acceptable Wait Times For Patrons At Transit Bus Stops By Time Of Day, Stephen Arhin

Mineta Transportation Institute Publications

The time spent waiting by bus patrons at bus stops is a primary measure for assessing the reliability of transit services. Uncertainty associated with waiting affects bus patrons’ perception of quality of the service provided. Consequently, this study aimed to determine patrons’ maximum and minimum acceptable wait times at bus stops in Washington, DC and to develop prediction models to provide decision-makers with additional tools for improving patronage.

The data used in this study was obtained by surveying 3,388 bus patrons at 71 selected bus stops in Washington, D.C. over an eight-month period. Data obtained from patrons included their ethnicity, …

Identification Of Bridges With Fracture-Prone Details, Theodore Hopwood Ii, Rick Younce, Sudhir Palle

Kentucky Transportation Center Research Report

Welded steel girder bridges can contain details that can high welding and service stresses and are termed constraintinduced fractures (CIF). The Kentucky Transportation Cabinet has steel bridges with weld details known to cause CIFs whose girders have experienced fracture events. The Cabinet’s bridge inventory was reviewed and additional candidate bridges with potential CIF details were identified. A review of bridge plans and pictures along with followup field investigations pinpointed bridges with CIF details that warrant up-close (i.e., arm’s length) inspections. Several uninspected bridges were identified as candidates for inspection to determine if they contain CIF details. Guidance is provided to …

18-01 Sustainable And Smart-Growth City Ranking: Multifaceted Transportation Performance Measures In Smart Cities, Jun-Seok Oh, Valerian Kwigizile, Ahmad Feizi

Transportation Research Center Reports

The concept of smart city is fast becoming a key instrument in transforming living environments in a way better to enhance operational efficiency of a transportation system. This study identifies a framework to assess transportation performance measures and smart-growth of cities around the U.S. The proposed assessment framework is comprised of the evaluation of individual criterion and the assessment of comprehensive results. The criteria are categorized into four groups including network performance, traffic safety, environmental impact, and physical activity. This study provides a multifaceted approach to integrate the criteria’s performance measures. As a case example, the proposed performance measures were …

Design And Preliminary Testing Of Demand-Responsive Transverse Rumble Strips, Md Shakhawat Hossen, Christopher Kappes, Mohamed Trabia, Brendan Morris, Jeewoong Park, Alexander Paz

Mechanical Engineering Faculty Research

Transverse rumble strips are common practice to alert drivers by engaging their auditory and tactile senses in addition to visual senses by traffic signals. However, continuous exposure to noise and vibration by transverse rumble strips often results in diminished effectiveness and erratic behaviors, leading to additional safety challenges. In response, demand-responsive transverse rumble strips were developed as traffic safety countermeasures that reduce unnecessary noise and vibration associated with transverse rumble strips by incorporating active control of the rumble strips. Rather than staying static, demand-responsive transverse rumble strips are activated based on the presence of pedestrians, at predesignated times, or in …

17-09 Assessing The Impact Of Air Pollution On Public Health Along Transit Routes, Stephen Mattingly, Kyung (Kate) Hyun, Shirin Kamali Rad, Mehrdad Arabi, Sina Famili

Transportation Research Center Reports

Transportation sources account for a large proportion of the pollutants found in most urban areas. Also, transportation activity and intensity appear likely to contribute to the risk of respiratory disease occurrence. This research investigates the impacts of transportation, urban design and socioeconomic characteristics on the risk of air pollution-related respiratory diseases in two of the biggest MSAs (Metropolitan Statistical Areas) in the US, Dallas-Fort Worth (DFW) and Los Angeles at the block group (BG) level, by considering the US Environmental Protection Agency’s respiratory hazard quotient (RHQ) as the dependent variable. The researchers identify thirty candidate indicators of disease risk from …

Evaluation Of Guardrail Needs And Update Of Guardrail Rating Program, Brian K. Howell, William Nicholas Staats, Nancy Albright

Kentucky Transportation Center Research Report

The Kentucky Transportation Cabinet (KYTC) seeks to reduce the frequency of roadway departure crashes, which often prove fatal. Roadside barriers such as guardrail have proven effective at mitigating these crashes, however, the demand for installations is high throughout the state. KYTC must prioritize prospective guardrail locations to match available funds with the most critical, or unsafe, sites. The current guardrail rating program (GRP) was established in 1989 to identify and prioritize guardrail needs. Despite periodic updates, the existing program no longer meets the transportation industry’s safety guidelines and policies. The Kentucky Transportation Center (KTC) studied national and state guardrail practices …