Transportation Engineering Commons^™

Characterization Of Sediment Loads And Size Distribution In Nebraska Roadway Runoff, Bruce I. Dvorak, David M. Admiraal, Pavel Shrestha

Nebraska Department of Transportation: Research Reports

The Nebraska Department of Transportation (NDOT) must manage sediment, and pollutant loads from roadway runoff to meet stormwater regulations. The SAFL Baffle, a hydrodynamic separator used by NDOT, depends on reliable estimates of total suspended solids (TSS) and particle size distribution (PSD). However, limited data exists for Nebraska roadways. In this study stormwater runoff was monitored at four NDOT-maintained sites, two in Lincoln and two in Beatrice, over 1.5 years to characterize TSS and PSD and to evaluate SAFL Baffle performance using the SHSAM model. Results showed large variability across sites and seasons. Median TSS ranged from 158 to 580 …

Assessment Of Winter Maintenance Performance Objectives Using Maintenance Decision Support System, Curtis L. Walker, Mark R. Anderson, Aemal Khattak, Thomas Kauzlarich, Abdul Farhan

Nebraska Department of Transportation: Research Reports

It is important for transportation agencies to assess their winter maintenance operations performance to identify areas for improvement and/or resource investment to maintain optimal levels of service, mobility, and safety. This study explores nine winter snowstorms in Nebraska during the 2023-2024 winter season across 20 road segments, 12 of which were along the Interstate-80 corridor. Datasets explored include meteorological information, traffic mobility insights, winter maintenance operations activities, and road conditions before, during, and after the periods of accumulating snowfall. Statistical analyses explored correlations and quantitative relationships among these datasets, while visual dashboards were developed to promote more qualitative considerations of …

The Effect Of The Socioeconomic Variety In Greater Cairo On Transport Mode Choices, Rafik Yanni

Theses and Dissertations

In the last decade, Egypt has experienced a noticeable upgrade in its infrastructure investment, implementing a lot of transport projects, especially in the Greater Cairo region. In a city with over 20 million residents, variations lie in socioeconomic elements like income, age, gender, and neighborhood, which shape people’s choice of mobility modes based on their culture and lifestyle. The questions then become: whom are these new projects targeting? What are the barriers to using these services? And is there any willingness to change commuting habits if conditions changed? This thesis investigates how the socioeconomic variety in Greater Cairo metropolitan region …

Trip Generation Model For Mixed-Use Development In Klang Valley, Malaysia., Goh Boon Hoe

Student Works (2020-2029)

Mixed-Use Developments (MXDs) are single development projects that integrate and interact with different land uses, such as offices, retail, restaurants, entertainment venues, hotels, and/or residential areas. MXDs are internally connected, allowing users of different land uses to share internal streets, walkways, driveways, and parking spaces. Traffic is estimated to be reduced with such developments. Currently, in Malaysia, there is no standard procedure to estimate the MXD trip generation rates. The Malaysian Trip Generation Manual (MTGM) 2010 is the guideline used to forecast future trips for a single land use and hence, by summing the trip generation rates for multiple land …

Optimal Placement Of Electric Vehicle Chargers: A Mixed-Integer Linear Programming Model, Joubin Zahiri Khameneh, Emmanuel Fagbenle

Faculty Publications

Electric vehicle adoption is growing, but New Hampshire lags in public charging infrastructure, especially in rural areas. This gap increases range anxiety and economic inefficiencies. In this study, we developed a mixed-integer linear programming (MILP) model to optimally locate new electric vehicle chargers statewide, maximizing coverage and equity under budget constraints. The model includes geographic coverage requirements, population-weighted equity, capacity limits, and a $28 million budget. Moreover, the model recommends 855 Level 2 chargers and 149 Direct Current Fast Chargers (DCFCs) across 247 ZIP Codes, nearly doubling public charging capacity and achieving 98.8% coverage within defined service radii. The plan …

The Rise In Height And Curb Weight Of The Top-Selling Vehicles In The United States From 1991 - 2025: Implications For Engineering Design And Vulnerable Road Users, Samuel L. Steinman-Friedman

Civil Engineering Theses

Road fatalities are higher in the United States than in other high-income regions. In 2024, 39,254 people died on roads in the United States compared to 19,940 in the European Union. These two regions have comparable exposure metrics, such as population size, roadway network length, and fatalities per mile traveled. Light trucks dominate the U.S. market, whereas hatchbacks are prevalent in Europe. The trendline of the average height and curb weight of the top-selling vehicles in the United States has increased by 0.24 inches and 23.52 pounds per year since 1991. The average 2025 top-selling U.S. passenger vehicle is 7.5 …

Concord Public Transportation Improvement Project, Jacob Holt

Honors Theses and Capstones

The capital city of Concord, New Hampshire, has been served by Concord Area Transit (CAT) since 1989. Despite continued population growth and economic development within the city, CAT’s fixed route bus system has remained unaltered since 2011. The purpose of this project is to rework the CAT system to provide service that better aligns with Concord resident’s current needs. A public survey was conducted to gather data regarding Concord resident’s needs, habits, and perception of the existing system, which was used in the development of the revised system. The project includes suggestions for both system-wide and route-specific modifications. Key changes …

Evaluation Of Critical Shear Strength Of Soils In Nebraska Based On Revised Cpt, Chung R. Song, Bashar Al-Nimri, Basil Abu Al Sha'r, Dhurba R. Pandey, Jongwan Eun, Seunghee Kim

Nebraska Department of Transportation: Research Reports

This study evaluated the “Fully Softened Shear Strength (FSSS)” of soils in Nebraska based on a revised Cone Penetration Test(CPT) method. FSSS is a unique strength condition that soils show substantially reduced strength during rainy seasons, eventually causing failure of slopes and other structures.

The revised CPT was adapted to inject water at targeted depths, inducing controlled moisture infiltration and capturing real-time soil softening over designated intervals of 30, 60, or 90 minutes. Through tip resistance (qc) and sleeve friction (fs) measurements under “in-situ” and “wet” conditions, the test effectively identified fully disturbed/low strength zones around the sleeve. Simultaneous sampling …

The Use Of Recycled Plastic In Asphalt Pavements: Feasibility Study, Isabella Bueno, Robert Rea, Jamilla Teixeira

Nebraska Department of Transportation: Research Reports

The plastics industry has been actively exploring new end-market opportunities for the more than 35 million tons of waste plastics generated annually. The use of recycled WP in asphalt presents an opportunity to improve pavement performance while reducing the growing amount of WP being landfilled or released into the environment. However, the use of WP in asphalt mixtures poses challenges due to variations in plastic composition and the presence of non-plastic contaminants. The absence of standardized procedures has resulted in inconsistent integration methods and unclear roles of WP within asphalt concrete (AC) mixtures. Therefore, the goal of this multiphase study …

Development And Evaluation Of Crashworthy Approach Guardrail Transition With Increased Span Length Between Concrete Bridge Rail And First Transition Post – Phase I, Tewodros Yosef, Qusai Alomari, Ronald K. Faller, Robert W. Bielenberg, Scott Rosenbaugh

Nebraska Department of Transportation: Research Reports

This study developed and evaluated a 34-in.-tall Nebraska Department of Transportation (NDOT) thrie-beam approach guardrail transition (AGT) with an increased span between the concrete buttress end and the first transition post. The objective was to accommodate a wide range of common obstructions near bridge ends, including abutments, wing walls, drainage features, and utilities. A survey of NDOT districts identified critical obstruction geometries and informed design criteria. Most NDOT districts indicated that a maximum span of about 4 ft would be sufficient, and some preferred spans up to 6 ft. To accommodate a wider range of obstructions, the first transition post …

Assessment Of Truck Parking Demand And Safety During Normal And Severe Weather Conditions In Nebraska, Nathan Huynh, Li Zhao, Zhenghong Tang, Aida Riahifar, Jahangeer Jahangeer

Nebraska Department of Transportation: Research Reports

This project examined truck parking capacity, demand, and utilization patterns along I-80 in Nebraska. The objectives were to (1) document the capacity of public and private truck parking facilities along I-80, (2) analyze spatial and temporal trends in parking demand, (3) develop models to predict occupancy at parking facilities, (4) identify clusters of undesignated parking during inclement weather, and (5) assess whether truck parking shortages contribute to truck-involved crashes. Within a one-mile buffer of I-80, 21 public facilities and 49 private facilities were identified. The spatiotemporal analysis of these public and private truck parking facilities using the National Agriculture Imagery …

Enhancing Traffic State Estimation At Bottlenecks Through Improved Demand Modeling: A Greenshields-Grounded Approach, Yuyan Annie Pan, Xianbiao Hu, Qing Tang, Yanyan Chen, Xuesong (Simon) Zhou

Civil & Environmental Engineering Faculty Publications

Accurate estimation of traffic state under oversaturated conditions is fundamental to a wide range of transportation applications. While intuitive, volume-to-capacity (q/qc) ratio-based link performance functions (LPF) are challenged by the U-shaped pattern of real-world speed-flow plots, which contradict the monotonic assumptions of link performance models such as the Bureau of Public Roads (BPR) function, particularly when q/q_c ≥ 1. This study addresses this critical gap by proposing an enhanced demand estimation method grounded in the Greenshields model, incorporating a real-time inflow correction factor to more accurately capture traffic demand at bottlenecks. In parallel, a modified LPF is introduced, replacing …

Adaptive Electric Vehicle Routing And Charging With Deep Reinforcement Learning, Mandana Farhang Ghahfarokhi, Hyoshin Park, Venktesh Pandey, Gyugeun Yoon

Engineering Management & Systems Engineering Faculty Publications

As electric vehicles (EVs) gain popularity, efficient routing and charging solutions remain challenging due to time-dependent travel variability, sparse charging infrastructure, and heterogeneous user preferences. To address these challenges, this paper introduces a decision-support system that integrates three complementary methods: Temporal Multimodal Multivariate Learning (TMML) for real-time characterization of travel time uncertainty, Time-Dependent Shortest Path (TDSP) for reliability-aware route choice, and Deep Q-Network (DQN) reinforcement learning for adaptive charging decisions in sparse infrastructure environments. TMML updates link-level travel time distributions in real-time through Bayesian inference with cluster-based propagation, reducing uncertainties across the network. TDSP leverages these updated distributions to estimate …

Seat Belt Data Collection Methods: A Comparison Between States And National Guidelines, Madison R A Richards

Williams Honors College, Honors Research Projects

Thousands of fatalities related to vehicle crashes occur every year. One method to reduce fatalities is to encourage seat belt use compliance. To promote statistics regarding seat belt use, there first must be reliable data on seat belt compliance and this comes from good survey design.

This report is a comparative analysis of seat belt data collection methodologies for Ohio, Michigan, and Indiana, in addition to an evaluation of how each state aligns with standards set by the National Highway Traffic Safety Administration (NHTSA). The framework for this analysis focuses on NHTSA’s five core survey design requirements: selection of observation …

Feasibility Of Quantifying The Dosage Of Zycotherm In Its Modified Asphalt Binders, Susmita Acharjee

College of Graduate Studies: Theses & Dissertations

The quantification of low-percentage additives in asphalt binders is challenging due to their minimal concentration and the complex composition of the binder matrix. Zycotherm, a nano-organosilane anti-stripping additive, is typically used in very small dosages (0.05%–0.20%), making its detection and quantification particularly difficult. This study investigated the feasibility of estimating Zycotherm dosage in asphalt binders by examining chemical and rheological and moisture responses. Two asphalt binder grades, PG 64-22 and PG 76-22, were modified with Zycotherm at dosages of 0.05%, 0.10%, 0.15%, and 0.20% by weight of binder, along with corresponding base binders. Laboratory experiments were conducted using Fourier Transform …

A Novel Federated Llm Framework For Distributed Traffic Modelling In Intelligent Transportation Systems, Seerat Kaur

Theses and Dissertations (Comprehensive)

Intelligent transportation systems (ITS) depend on accurate traffic prediction to support congestion management, infrastructure planning, and real-time operational decisions. Despite substantial progress in data-driven forecasting, several challenges continue to limit practical deployment: traffic data is distributed across independent regional authorities, making centralized aggregation infeasible, standard federated aggregation strategies ignore traffic-specific characteristics that meaningfully affect model quality, and existing models produce only numerical outputs without interpretable reasoning that urban planners can act upon. This thesis addresses these challenges through four contributions that collectively advance privacy-preserving, explainable, and scalable traffic forecasting.

The first contribution provides a systematic review of 129 peer-reviewed publications, …

Statewide Corridor Evacuation Response And Re-Entry Behaviors In Florida During Hurricane Irma, Xin Wang, Yuan Zhu, Hong Yang, Kun Xie

Electrical & Computer Engineering Faculty Publications

Hurricane Irma stands as one of the most destructive tropical storms to make landfall in the United States, particularly impacting the State of Florida, where it prompted the largest evacuation in history with approximately 7 million residents. The profound consequences of mass evacuation underscore the critical need to understand travel behaviors during hurricane evacuation and the recovery process. This research analyzes statewide evacuation and re-entry patterns, leveraging diverse datasets, including TTMS data from main corridors and GIS data. A statewide corridor-based empirical analysis framework is constructed to characterize evacuation and re-entry response patterns using sensor-based traffic observations. The results show …

Integrated Corridor Management Framework For Severe Freeway Incidents, Sanjida Afroz Iqra

Graduate Studies Theses and Dissertations 2026

Traffic incidents are a major source of non-recurrent congestion on urban freeways, generating substantial mobility, safety, and economic impacts. Severe incidents that block multiple or all travel lanes are particularly disruptive because they degrade freeway operations and propagate congestion onto surrounding arterials. Effective Integrated Corridor Management (ICM) requires the ability to identify severe incidents, estimate their network-wide impacts, and anticipate the traffic conditions and driver behaviors that contribute to instability. This dissertation develops a data-driven ICM framework to address these challenges using real-world incident, crash, detector, and connected vehicle data from major Central Florida corridors, including I-4 and SR-417. The …