Transportation Engineering Commons^™

Safety Evaluation Of Innovative Intersection Designs: Diverging Diamond Interchanges And Displaced Left-Turn Intersections, Ahmed Abdelrahman

Electronic Theses and Dissertations, 2020-2023

Diverging diamond interchanges (DDIs) and Displaced left-turn intersections (DLTs) are designed to enhance the operational performance of conventional intersections that are congested due to heavy left-turn traffic volumes. Since drivers are not familiar with these types of intersections, there is a need to evaluate their safety performance to validate their effect, and to estimate reliable and representative Crash Modification Factors (CMFs). The safety evaluation was conducted based on three common safety assessment methods, which are before-and-after study with comparison group, Empirical Bayes before-and-after method, and cross-sectional analysis. Furthermore, since DLTs showed poor safety performance, the study also investigated the operational …

Development Of An Ndt Tool For In-Situ Assessment Of Prestress Loss, Bibo Zhong, Jinying Zhu, George Morcous

Nebraska Department of Transportation: Research Reports

The research objective is to develop a non-destructive testing (NDT) method to evaluate the prestress loss in prestressed concrete bridge girders using ultrasonic waves. The work principle is based on acoustoelastic effect - ultrasonic wave velocity varies with stress level in prestressed concrete. A self-reference test setup was proposed to measure wave velocity in two orthogonal directions (prestress and unstressed directions) in the girder. This setup will be able to reduce effects of material variation and temperature change.

The concept was first validated on small concrete specimens (cylinders and beams) in laboratory. A signal analysis algorithm was developed to reliably …

Smartphone Sensor-Based Pedestrian Activity Recognition For P2v Communication And Warning System, Dhrubo Hasan Chowdhury

Electronic Theses and Dissertations, 2020-2023

The ubiquity of smartphones has made a remarkable influence on everyone's day to day life. Variety of useful built-in sensors provide smartphones with a convenient floor for data collection and analysis. Application development based on the user's location and movement is not a difficult task nowadays. But injuries and deaths due to smartphone-distracted movement on roadways is on the increase. This study explores the capabilities of smartphone inertial sensors for pedestrian activity recognition. Smartphone distracted movements can be predicted from the associated pedestrian's posture, thus inertial sensors can provide effective solution for this specific task. Volunteers were asked to perform …

Traffic Speed Prediction And Mobility Behavior Analysis Using On-Demand Ride-Hailing Service Data, Jiechao Zhang

Electronic Theses and Dissertations, 2020-2023

Providing accurate traffic speed prediction is essential for the success of Intelligent Transportation Systems (ITS) deployments. Accurate traffic speed prediction allows traffic managers take proper countermeasures when emergent changes happen in the transportation network. In this thesis, we present a computationally less expensive machine learning approach XGBoost to predict the future travel speed of a selected sub-network in Beijing's transportation network. We perform different experiments for predicting speed in the network from future 1 min to 20 min. We compare the XGBoost approach against other well-known machine learning and statistical models such as linear regression and decision tree, gradient boosting …

Prediction Of Pedestrians' Red Light Violations Using Deep Learning, Shile Zhang

Electronic Theses and Dissertations, 2020-2023

Pedestrians are regarded as Vulnerable Road Users (VRUs). Each year, thousands of pedestrians' deaths are caused by traffic crashes, which take up 16% of the total road fatalities and injuries in the U.S. (FHWA, 2018). Crashes can happen if there are interactions between VRUs and motorized transportation. And pedestrians' unexpected crossings, such as red-light violations at the signalized intersections, would expose them to motorized transportation and cause potential collisions. This thesis is intended to predict the pedestrians' red-light violation behaviors at the signalized crosswalks based on an LSTM (Long Short-term Memory) neural network. With video data collected from real traffic …

Effect Of Temporal Instability Of Factors Contributing To Single-Vehicle Crash Severity--A Mixed Logit Approach, A. M. Hasibul Islam

Theses and Dissertations--Civil Engineering

This study investigates the factors associated with single-vehicle crash injury severity using five years (2014 – 2018) of crash data from Kentucky, USA, using a mixed (random-parameter) logit model. We also explore the temporal heterogeneity of the correlated factors across different times of the day. Most crash-severity models assume that the estimated parameters remain temporally stable. For instance, the effect of light conditions on crash severity may differ based on the time of the crash occurrence—noon vs. dusk. The temporal instability of the factors due to the time-of-day variation can lead to (under) overestimating the parameters that influence the development …

Valuing Public Transport Customer Amenities: International Transit Agency Practice, Chris De Gruyter, Graham Currie

Journal of Public Transportation

Public transport customer amenities cover a range of measures that can enhance the quality of the passenger experience, such as information provision and station quality. While much research has determined the value that users place on amenities, there is little understanding of current practice in the use of customer amenity valuations in project appraisal. A survey of transit agencies in 11 cities (Melbourne, Sydney, Brisbane, Perth, Auckland, London, Paris, Toronto, Vienna, Oslo and Singapore) was undertaken showing that Australasian cities, albeit Melbourne, generally have widespread inclusion of customer amenities as part of advanced appraisals for all relevant types of public …

Exploring Low-Carbon Bus Options For Urban Brt Systems: The Case Of Amman, Rana Imam, Seong-Cheol Kang, Diana Quezada

Journal of Public Transportation

Being able to provide high-quality, metro-like transit service at a fraction of the cost of other options, bus rapid transit (BRT) has been viewed as one of the most cost-effective public mass transport systems suitable for urban areas. Considering significant amounts of greenhouse gas (GHG) and air pollutant emissions are attributed to the transport sector, deploying low carbon buses for BRT systems should be of high priority. With a view to promoting low carbon buses instead of diesel buses for a BRT system currently being planned in Amman, Jordan, this paper evaluates several low carbon bus options – hybrid, plug-in …

Effect Of Socioeconomic And Demographic Factors Of Driver Residence On Crash Occurrence, Shraddha Sagar

Theses and Dissertations--Civil Engineering

In the U.S., road traffic crashes are a leading cause of death. Crash data from the state of Kentucky shows that the per capita crash rates and crash-related fatalities were higher than the national average for over a decade. In effort to explain why the U.S. Southeast experiences higher crash rates than other regions of the country, previous research has argued the region’s unique socioeconomic provide a compelling explanation. Taking this observation as a starting point, this study examines the relationship between highway safety and socioeconomic characteristics using an extensive crash dataset from Kentucky.

The primary goal of this research …

Modeling Of Incident Type And Incident Duration Using Data From Multiple Years, Sudipta Dey Tirtha

Electronic Theses and Dissertations, 2020-2023

We develop a model system that recognizes the distinct traffic incident duration profiles based on incident type. Specifically, a copula-based joint framework with a scaled multinomial logit model (SMNL) system for incident type and a grouped generalized ordered logit (GGOL) model system for incident duration to accommodate for the impact of observed and unobserved effects on incident type and incident duration. The model system is estimated using traffic incident data from 2012 through 2017 for the Greater Orlando region, employing a comprehensive set of exogenous variables – incident characteristics, roadway characteristics, traffic condition, weather condition, built environment and socio-demographic characteristics. …

Effects Of Cellulose Nano-Fiber As An Additive On Performance Of Asphalt Binders And Mixes, Marco Paulo Pereira Castro

Electronic Theses and Dissertations

Findings of a study conducted on asphalt binders and mixes modified by addition of cellulose nanofiber (CNF) to evaluate the feasibility of them as an additive is presented in the current thesis. Cellulose Acetate (CA) is an ester of cellulose and is obtained by the reaction of cellulose with acetic anhydride and acetic acid in the presence of sulfuric acid. Due to its high temperature sensitivity, high ductility, large surface area, high strain resistance, and low electrical resistivity, cellulose acetate can be used for several application. The question is if CNF can be used as an additive in the asphalt, …

Covid-19 And Public Transportation: Current Assessment, Prospects, And Research Needs, Alejandro Tirachini, Oded Cats

Journal of Public Transportation

The COVID-19 pandemic poses a great challenge for contemporary public transportation worldwide, resulting from an unprecedented decline in demand and revenue. In this paper, we synthesize the state-of-the-art, up to early June 2020, on key developments regarding public transportation and the COVID-19 pandemic, including the different responses adopted by governments and public transportation agencies around the world, and the research needs pertaining to critical issues that minimize contagion risk in public transportation in the so-called post-lockdown phase. While attempts at adherence to physical distancing (which challenges the very concept of mass public transportation) are looming in several countries, the latest …

Extracting Bus Transit Boarding And Alighting Information Using Smart Card Transaction Data, Zhen Chen, Wei Fan

Journal of Public Transportation

The smart card–based automated fare collection (AFC) technologies provide new opportunities for transportation data collection since smart card data (SCD) contain a significant amount of archived information that can be gathered and leveraged to help estimate public transit origin-destination (OD) matrices. Both boarding and alighting location detection are important particularly when there is no automatic vehicle location (AVL) system or other information in the database. With the analysis of raw data using limited information in this paper, an algorithm for boarding stop identification is presented after the trip direction and boarding cluster identification. Alighting stops are then identified based on …

Mobility-As-A-Service: Assessing Performance And Sustainability Effects Of An Integrated Multi-Modal Simulated Transportation Network, Mohamed El-Agroudy

Electronic Theses and Dissertations, 2020-2023

Advances in information technology services have seen profound impacts on the state of transport services in the urban traffic environment. Mobility-as-a-Service (MaaS) represents the digital consolidation of users, operators, and public-private managing entities to provide totally comprehensive, integrated trip-making services. Users now enjoy extra flexibility for trip-making with new modal alternatives such as micro-mobility (e.g Lime Bikes, Spin Scooters) and rideshare (e.g. Lyft, Uber). However, current knowledge on the performance and interactive effects of these newer alternative modes is vague if not inconsistent. As such, these effects were studied through micro-simulation analysis of a multi-modal urban corridor in Orlando, Florida. …

Evaluation Of Safety And Mobility Benefits Of Connected And Automated Vehicles By Considering V2x Technologies, Md Hasibur Rahman

Electronic Theses and Dissertations, 2020-2023

The recent development in communication technologies facilitates the deployment of connected and automated vehicles (CAV) which are expected to change the future transportation system. CAV technologies enable vehicles to communicate with other vehicles through vehicle-to-vehicle (V2V) communications and the infrastructure through Vehicle-to-infrastructure (V2I) communications. Since the real-world CAV data is not currently available as of today, simulation is the most commonly used platform to evaluate the future V2X system. Although several studies evaluated the effectiveness of CAVs in a small roadway network, there is a lack of studies analyzing the impact of CAVs at the network level by considering both …

A Deep Learning Approach For Real-Time Crash Risk Prediction At Urban Arterials, Pei Li

Electronic Theses and Dissertations, 2020-2023

Real-time crash risk prediction aims to predict the crash probabilities within a short time period, it is expected to play a crucial role in the advanced traffic management system. However, most of the existing studies only focused on freeways rather than urban arterials because of the complicated traffic environment of the arterials. This thesis proposes a long short-term memory convolutional neural network (LSTM-CNN) to predict the real-time crash risk at arterials. The advantage of this model is it can benefit from both LSTM and CNN. Specifically, LSTM captures the long-term dependency of the data while CNN extracts the time-invariant features. …

Corrigendum To “Heavy Metal Ion Detection On A Microspot Electrode Using An Optical Electrochemical Probe” [Electrochem. Commun. 86 (2018) 94–98], Santanu Roy, Abhijeet Prasad, Rahul Tevatia, Ravi Saraf

Mid-America Transportation Center: Final Reports and Technical Briefs

The authors regret to inform an error. Ravi F. Saraf of this pub- lication discloses financial interest in Vajra Instrument as its founder and President. In accordance with its Conflict of Interest policy, the University of Nebraska-Lincoln’s Conflict of Interest in Research Committee has determined that this must be disclosed. The authors would like to apologise for any inconvenience caused.

The Relationship Between Roadway Homogeneity And Network Coverage For Network Screening, Riana Tanzen

Theses and Dissertations--Civil Engineering

In the context of transportation safety engineering, network screening is a method of identifying and prioritizing high-risk locations for potential safety investment. Since its release, the Highway Safety Manual (HSM) has facilitated the adoption of Safety Performance Functions (SPF) to predict the number of crashes for the network screening of any facility type. The predictive model becomes more reliable when developed from crash data with homogeneous roadway segments and this homogeneity can be attained by applying specific geometric attributes to the dataset. The caveat to this method is the requirement of adjustment factors (AFs) to adjust the predicted estimate for …

Design And Analysis Of A Pavement Marker Detection System, Timothy L. Johnson Ii

Theses and Dissertations--Civil Engineering

Personal injuries and property damage due to the failure of snow-plowable pavement markers which detach from pavement surfaces has led to the development of new all-plastic pavement markers which are located entirely below the planar surface of the pavement. The new all-plastic design pushes existing solutions used to avoid striping over highway reflectors into obsolescence since current solutions operate using electromagnets to sense the metal housings of snow-plowable pavement markers. A replacement solution is currently sought by the highway maintenance industry and three different marker detection methods were developed and tested on real-world highways with both new and aging pavement …

Methodology For Quantifying Resiliency Of Transportation Systems, Hannah Rose Russell

Doctoral Dissertations and Master's Theses

The National Science Foundation’s definition of resiliency is “the ability to prepare and plan for, absorb, recover from, or more successfully adapt to actual or potential adverse events” (National Science Foundation, 2016). While this definition is informative and useful, it lacks a quantitative reference. There is a need for a method of quantifying resilience to better plan and prepare for system wide disruptions. The research effort described herein provides a quantifiable measures of system resiliency, consistent with NSF’s definition. Fundamentally, a system disruption can be partitioned into five distinctive states: the stable pre-event state, the absorption state, the disrupted state, …

Life Cycle Information Models With Parameter Uncertainty Analysis To Facilitate The Use Of Life-Cycle Assessment Outcomes In Pavement Design Decision-Making, Chaitanya Ganesh Bhat

Dissertations, Master's Theses and Master's Reports

The objective of this dissertation is to develop Life Cycle Information Models (LCIMs) to promote consistent and credible communication of potential environmental impacts quantified through Life-Cycle Assessment (LCA) methodology. The introduction of Life Cycle Information Models (LCIMs) will shift the focus of pavement LCA stakeholders to collect reliable foreground data and adapt to consistent background data present within LCIMs. LCA methodology requires significant Life Cycle Inventory (LCI) data to model real world systems and quantify potential environmental impacts. The lack of guidance in ISO standards on consistently compiling LCI data and defining protocols for modeling lowers the reliability of LCA …

The Laboratory Performance And Aging Characteristics Of Rubber Modified Asphalt Mixture Using A Dry Process, Dongdong Ge

Dissertations, Master's Theses and Master's Reports

The accumulation of waste tires generates severe environmental issues. Using crumb rubber processed from waste tires on the pavement could relieve the pressure of waste tire on the environment and improve the performance of the pavement as well. The application of crumb rubber on the pavement using the dry process was proved to be a cost-effective strategy in some projects, however, the interaction between the rubber and asphalt binder was unknown in the rubber modified asphalt mixture using the dry process, especially when reclaimed asphalt pavement was adopted. The performance improvement of the rubber particle to the asphalt mixture was …

Feasibility Study Of Development Of Ultra-High Performance Concrete (Uhpc) For Highway Bridge Applications In Nebraska, Flavia Ribeiro Furtado De Mendonca, Mostafa Abo El-Khier, George Morcous, Jiong Hu

Nebraska Department of Transportation: Research Reports

Ultra-high performance concrete (UHPC) is a new class of concrete that has superior mechanical, durability, and workability properties that far exceed those of conventional concrete. To achieve these properties, a specific mix design with a very dense internal structure, fiber reinforcement, and low water-to-binder ratio (w/b) is commonly used. The goal of this research is to develop a non-proprietary UHPC mix with constituent materials that are readily available in the state of Nebraska for bridge construction applications. In developing this mix, the particle packing model is used, and an experimental study of the impact of various design parameters on the …

Evaluation Of Tie-Bar Anchoring Methods: Non-Shrink Grout Vs. Epoxy, Wally Heyen, Lieska Halsey, Tim Krason, Brandon Varilek, David Hansen

Nebraska Department of Transportation: Research Reports

Tie bars are epoxy coated steel bars that connect the longitudinal joints in concrete pavement. Tie bars prevent faulting and joint separation between lanes Tie bars can be placed into the plastic concrete or inserted after curing by drilling and anchoring with epoxy or non-shrink grout. The specification for the tie bars requires the use of a No. 5 bar, 18 inches long and shall meet ASTM A775 / A775M [1], Section 1020.The Nebraska Department of Transportation “Standard Specifications for Highway Construction,” (Section 603.03) requires contractors to mechanically insert tie bars into the face of pavements during construction. Tie bars …

Influence Of Curing Conditions On Concrete Specimens (Cylinders) In Hot And Cold Weather In The Field, Wally Heyen, Lieska Halsey, Tim Krason, David Hansen

Nebraska Department of Transportation: Research Reports

No abstract provided.

Estimating Free-Flow Speed With Lidar And Overhead Imagery, Armin Hadzic

Theses and Dissertations--Computer Science

Understanding free-flow speed is fundamental to transportation engineering in order to improve traffic flow, control, and planning. The free-flow speed of a road segment is the average speed of automobiles unaffected by traffic congestion or delay. Collecting speed data across a state is both expensive and time consuming. Some approaches have been presented to estimate speed using geometric road features for certain types of roads in limited environments. However, estimating speed at state scale for varying landscapes, environments, and road qualities has been relegated to manual engineering and expensive sensor networks. This thesis proposes an automated approach for estimating free-flow …

Accessibility And Equity Analysis Of Common Carrier Parcel Lockers At Transit Facilities In Portland, Oregon, Katherine Keeling, Jaclyn S. Schaefer, Miguel Figliozzi

Civil and Environmental Engineering Faculty Publications and Presentations

Transit goals have typically focused on commuter trips but facilitating urban last-mile freight logistics is a potential strategy to increase transit ridership and mitigate the demands of parcel distribution on the transportation network. Presently, most parcel lockers operate out of private businesses, but consumer surveys have found that transit users may be interested in locker facilities at transit connections. The implementation of an unmanned, secure, common carrier parcel locker system could have benefits for non-transit users as well. Consolidation of deliveries is expected to benefit courier companies by allowing operations at increasingly competitive rates, and retailers and consumers benefit from …

Lagrangian Relaxation Method For Integrated Vehicles And Drones Routing Model, Perawit Charoenwut

Chulalongkorn University Theses and Dissertations (Chula ETD)

Nowadays, e-commerce increases parcel transportation demand year by year. Many companies are seeking the way to improve performance of delivery service and cost-efficiency. One among many solutions is using a drone attached with a truck for the last mile delivery. A drone can be launched from either depot or truck and returned to the depot or wait for the truck to take them back from the docking station around the delivery area. The vehicle routing problem with drones considers truck- and drone-route simultaneously. It is an enormous problem that cannot be solved by a normal linear programming method. This research …

Transit Agencies Performance Assessment And Implications, Parisa Hajibabaee

Graduate Theses, Dissertations, and Problem Reports (ETD)

Although most transit systems operate in small urban and rural areas in the United States, these systems have rarely received the same attention as their urban counterparts, both in terms of ensuring the efficiency and effectiveness of their operations and understanding the factors that affect their performance. This thesis's main goals are to assess the performance of rural and small urban public transit agencies and help them evaluate adopting a ridehailing program, thereby improving their performance. We applied operations research and decision-making tools to two public transit projects in small urban and rural areas. The first project focuses on three …

Effect Of Binder Modification And Aggregate Size On Modulus And Fatigue Of Asphalt Concrete, Elizabeth Bashiti

Graduate Theses, Dissertations, and Problem Reports (ETD)

Asphalt concrete is one of the main ingredients used in the paving of roadways across the globe. These roadways have been deteriorating from overuse, under design, and a lack of understanding of the engineering properties. In the asphalt community, it is agreed upon that polymer modifiers and aggregate size have comparable impacts on the performance of a pavement, such as, low creep at high temperatures, high ductility at low temperatures, high toughness, resistance to moisture and temperature, high cohesive and adhesive strength. With all of these advantages, it has been often assumed that polymer modifiers extend/improve the expected life of …