Transportation Engineering Commons^™

Large Eddy Simulations Of Wind Shear From Passing Vehicles Under A Freeway Overpass, Hamid Rahai, Assma Begum

Mineta Transportation Institute

California is moving toward a 100% clean energy future, and expanded wind energy will be a major component of the state’s future energy portfolio. Innovations in wind energy resources will move California closer to achieving its goal. To gain a better understanding of transient pressure and the wind shear generated at the bridge poles from passing vehicles, this study performed large-eddy simulations of a vehicle (also called an Ahmed body) moving under a freeway overpass at a distance of 0.75 w (width) from the bridge poles. Results include transient contours of mean velocity, turbulent kinetic energy, vorticity, and pressure around …

Damage Detection And Damage Localization In Bridges With Low-Density Instrumentations Using The Wave-Method: Application To A Shake-Table Tested Bridge, Mehran Rahmani, Xintong Ji, Sovann Reach Kiet

Mineta Transportation Institute

This study presents a major development to the wave method, a methodology used for structural identification and monitoring. The research team tested the method for use in structural damage detection and damage localization in bridges, the latter being a challenging task. The main goal was to assess capability of the improved method by applying it to a shake-table-tested prototype bridge with sparse instrumentation. The bridge was a 4-span reinforced concrete structure comprising two columns at each bent (6 columns total) and a flat slab. It was tested to failure using seven biaxial excitations at its base. Availability of a robust …

Wastewater-Derived Ammonia For A Green Transportation Fuel, Joseph Kalman, Maryam Haddad

Mineta Transportation Institute

The energy-water nexus (i.e., availability of potable water and clean energy) is among the most important problems currently facing society. Ammonia is a carbon-free fuel that has the potential to reduce the carbon footprint in combustion related vehicles. However, ammonia production processes typically have their own carbon footprint and do not necessarily come from sustainable sources. This research examines wastewater filtration processes to harvest ammonia for transportation processes. The research team studied mock wastewater solutions and was able to achieve ammonia concentrations above 80%(nanofiltration) and 90% (reverse osmosis). The research team also investigated the influence of transmembrane pressure and flow …

Manual For Asphalt Pavement Repair And Resurfacing Preparation, Dingxin Cheng, Gary Hicks, Roger D. Smith

Mineta Transportation Institute

Timely repairs of pavement defects are essential in protecting an important investment and asset that public agencies have. These repairs may be made as durable “stand-alone” repairs of isolated problems, or as part of preparations for a total resurfacing. This manual provides basic information on the planning, materials and construction aspects of common pavement repairs such as crack sealing, crack filling, and patching, as well as a broader look at other preparations needed for total resurfacing a pavement, whether the resurfacing is a surface treatment or a thin hot mix asphalt (HMA) overlay.

Connected Simulation For Work Zone Safety Application, Vahid Balali

Mineta Transportation Institute

Every year, over 60,000 work zone crashes are reported in the United States (FHWA 2016). Such work zone crashes have resulted in over 4,400 fatal and 200,000 non-fatal injuries in the last 5 years (FHWA 2016, BLS 2014). Apart from the physical and emotional trauma, the annual cost of these injuries exceeds $4 million-representing significant wasted resources. To improve work zone safety, this research developed a system architecture for unveiling high-risk behavioral patterns among highway workers, equipment operators, and drivers within dynamic highway work zones. This research implemented the use of a connected virtual environment, which is an immersive hyper-realistic …

Contracting Strategies: A Different Approach To Address Long-Term Performance, Maria Calahorra-Jimenez

Mineta Transportation Institute

For cost-efficiency, public safety, and sustainability, improving long-term performance in highway projects is imperative for public administrations. Project delivery and procurement methods provide an opportunity to align design and construction processes with this goal. While previous studies have explored whether project delivery methods impact the long-term performance of highway projects, these studies did not focus on how core elements within project procurement relate to long-term performance. Thus, to fill this gap, this research explores how and to what extent long-term evaluation criteria are considered in design-build best-value procurement of highway projects. To this end, the team conducted content analysis on …

Managing The Curb: Understanding The Impacts Of On-Demand Mobility On Public Transit, Micromobility, And Pedestrians, Susan Shaheen, Elliot Martin, Adam Cohen, Jacquelyn Broader, Richard Davis

Mineta Transportation Institute

In recent years, innovative mobility and shifts in travel and consumption behavior are changing how people access and use the curb. Shared mobility—the shared use of a vehicle, bicycle, scooter, or other mode—coupled with outdoor dining, curbside pick-up, and robotic delivery are creating new needs related to the planning, management, and enforcement of curb access. This study examines curb planning and management from several angles, such as safety, social equity, and multimodal connections. This research employs a multi-method approach to identify the changing needs for curb space management and how to meet these needs through new planning and implementation policies …

Covid-19 Public Transportation Air Circulation And Virus Mitigation Study, Aly Tawfik, Deify Law, Juris Grasis, Joseph Oldham, Moe Salem

Mineta Transportation Institute

COVID-19 may have forever changed our world. Given the limited space and air circulation, potential infections on public transportation could be concerningly high. Accordingly, this study has two objectives: (1) to understand air circulation patterns inside the cabins of buses; and (2) to test the impact of different technologies in mitigating viruses from the air and on surfaces inside bus cabins. For the first objective, different devices, metrics and experiments (including colored smoke; videotaping; anemometers; pressure differentials; particle counts; and 3D numerical simulation models) were utilized and implemented to understand and quantify air circulation inside different buses, with different characteristics, …

Assessing Public Health Benefits Of Replacing Freight Trucks With Cargo Cycles In Last Leg Delivery Trips In Urban Centers, Jennifer C. Hartle, Ossama (Sam) A. Elrahman, Cara Wang, Daniel A. Rodriguez, Yue Ding, Matt Mcgahan

Mineta Transportation Institute

Increased urbanization, population growth, and demand for time-sensitive deliveries means increased freight movement in cities, which contributes to emissions, noise, and safety concerns. One innovative mode gaining widespread attention for urban deliveries is cargo cycles—bicycles adapted for freight delivery. Despite the recognized potential and possible success of transporting at least 25% of freight via cycle, research remains limited. This research investigates the potential of cargo cycle delivery for last mile freight in Oakland, California, with a focus on the West Oakland neighborhood. The data collection included interviews, focus groups, vehicle field observation and counts, and traffic simulation modeling. The traffic …

Influence Of Level 1 And Level 2 Automated Vehicles On Fatal Crashes And Fatal Crash Occurrence, Hardik Gajera, Srinivas S. Pulugurtha, Sonu Mathew

Mineta Transportation Institute

Connected and automated vehicles (CAVs) are expected to improve safety by gradually reducing human decisions while driving. However, there are still questions on their effectiveness as we transition from almost 0% CAVs to 100% CAVs with different levels of vehicle autonomy. This research focuses on synthesizing literature and identifying risk factors influencing fatal crashes involving level 1 and level 2 CAVs in the United States. Fatal crashes involving level 0 vehicles—ones that are not connected and automated—were compared to minimize unobserved heterogeneity and randomness associated with the influencing risk factors. The research team used the fatal crash data for the …

Impact Of Dedicated Bus Lanes On Intersection Operations And Travel Time Model Development, Stephen Arhin, Babin Manandhar, Kevin Obike, Melissa Anderson

Mineta Transportation Institute

Over the years, public transit agencies have been trying to improve their operations by continuously evaluating best practices to better serve patrons. Washington Metropolitan Area Transit Authority (WMATA) oversees the transit bus operations in the Washington Metropolitan Area (District of Columbia, some parts of Maryland and Virginia). One practice attempted by WMATA to improve bus travel time and transit reliability has been the implementation of designated bus lanes (DBLs). The District Department of Transportation (DDOT) implemented a bus priority program on selected corridors in the District of Columbia leading to the installation of red-painted DBLs on corridors of H Street, …

Evaluation Of Polymer Binder Technisoil G5® In Concrete Mixture, Shadi Saadeh, Pritam Katawal

Mineta Transportation Institute

Plastic is everywhere, and with its increasing use in so many everyday materials, the production and demand of plastic has skyrocketed. Unfortunately, this has resulted in the accumulation of a mammoth amount of plastic waste and adverse effects on the environment. To optimize the huge amount of materials required by the pavement industry each year and reuse recycled plastics, the use of reclaimed asphalt pavement (RAP) has been common practice. This research studied the use of a binder completely made from recycled waste plastic named Technisoil G5® and compared it with performance grade PG 70-22 mix containing virgin aggregates and …

Protecting Our Community From The Hidden Vulnerabilities Of Today’S Intelligent Transportation Systems, Shahab Tayeb

Mineta Transportation Institute

The ever-evolving technology interwoven into the transportation industry leaves it frequently at risk for cyber-attacks. This study analyzes the security of a common in-vehicle network, the Controller Area Network (CAN), standard in most vehicles being manufactured today. Like many other networks, CAN comes with inherent vulnerabilities that leave CAN implementations at risk of being targeted by cybercriminals. Such vulnerabilities range from eavesdropping, where the attacker can read the raw data traversing the vehicle, to spoofing, where the attacker can place fabricated traffic on the network. The research team initially performed a simulation of CAN traffic generation followed by hardware implementation …

Investigating The Resilience Of Accessibility To Emergency And Lifesaving Facilities Under Natural Hazards, Chih-Hao Wang, Na Chen

Mineta Transportation Institute

Studying accessibility, including the resilience of city transportation networks, is critical to understand how these networks influence individuals’ mobility and lives. This study developed an analytical research framework to examine the resilience of accessibility to emergency and lifesaving facilities under the threats of natural hazards such as earthquakes and wildfires. With a cumulative-opportunity approach, the authors measured accessibility by counting emergency and lifesaving facilities (including parks, schools, hospitals, roads, and fire stations) that can be reached by driving at the census tract level in San Fernando Valley, CA. With the calculated accessibility, the authors run simulations to collect data showing …

Novel Eco-Friendly, Recycled Composites For Improved Ca Road Surfaces, Daniel Whisler, Rafael Gomez Consarnau, Ryan Coy

Mineta Transportation Institute

The continued use of structural plastics in consumer products, industry, and transportation represents a potential source for durable, long lasting, and recyclable roadways. Costs to dispose of reinforced plastics can be similar to procuring new asphalt with mechanical performance exceeding that of the traditional road surface.

This project examines improved material development times by leveraging advanced computational material models based on validated experimental data. By testing traditional asphalt and select carbon and glass reinforced composites, both new and recycled, it is possible to develop a finite element simulation that can predict the material characteristics under a number of loads virtually, …

Performance Testing Of Hot Mix Asphalt Modified With Recycled Waste Plastic, Shadi Saadeh, Pritam Katawał

Mineta Transportation Institute

Plastic pollution has become one of the major concerns in the world. Plastic waste is not biodegradable, which makes it difficult to manage waste plastic pollution. Recycling and reusing waste plastic is an effective way to manage plastic pollution. Because of the huge quantity of waste plastic released into the world, industries requiring a large amount of material, like the pavement industry, can reuse some of this mammoth volume of waste plastics. Similarly, the use of reclaimed asphalt pavement (RAP) has also become common practice to ensure sustainability. The use of recycled waste plastics and RAP in HMA mix can …

Enhancement Of Asphalt Performance By Graphene-Based Bitumen Nanocomposites, Sara Moghtadernejad, Ehsan Barjasteh, Ren Nagata, Haia Malabeh

Mineta Transportation Institute

As the State of California continues to grow, demand for enhanced infrastructure such as roadways and highways escalates. In view of the current average highway lifespan of 15–20 years, the improvement of asphalt binders leads to material sustainability by decreasing required maintenance and increasing the lifespan of roadways. In the present investigation, enhancement of asphalt binder properties was achieved by different methods of mixing varying compositions of graphene nanoparticles with an SBS polymer and asphalt binder. Additionally, experimental evaluation and comparison of the rheological and mechanical properties of each specimen is presented. Graphene nanoparticles have attracted great curiosity in the …

Robotic Parking Technology For Congestion Mitigation And Air Quality Control Around Park & Rides, Mahdi Yoozbashizadeh, Forouzan Golshani

Mineta Transportation Institute

A lack or limited availability for parking may have multiple consequences, not the least of which is driver frustration, congestion, and air pollution. However, there is a greater problem that is not widely recognized by the public, namely the negative effect on the use of transit systems due to insufficient parking spaces close to key transit stations. Automated parking management systems, which have been successfully deployed in several European and Japanese cities, can manage parking needs at transit stations more effectively than other alternatives. Numerous studies have confirmed that quick and convenient automobile access to park-and-ride lots can be essential …

Cycling Past 50: A Closer Look Into The World Of Older Cyclists, Carol Kachadoorian

Mineta Transportation Institute

This document reports on 2,300 responses to a nationwide survey of older adults who cycle. The survey, open from February through September 2020, includes questions about a rider’s cycling history, current cycling habits, and falls. It includes a visual preference survey of various cycling facilities and an online journaling option for two rides subsequent to completing the survey (results of the online journals will be available in the summer 2021). Responses reflect the impact of COVID-19 on older adults’ cycling habits, the impact of aging on ability and agility, the impact of the built environment, types of bicycles, and opportunities …

City Best Practices To Improve Transit Operations And Safety, Michelle Derobertis, Christopher E. Ferrell, Richard W. Lee, David Moore

Mineta Transportation Institute

Public, fixed-route transit services most commonly operate on public streets. In addition, transit passengers must use sidewalks to access transit stops and stations. However, streets and sidewalks are under the jurisdiction of municipalities, not transit agencies. Various municipal policies, practices, and decisions affect transit operations, rider convenience, and passenger safety. Thus, these government entities have an important influence over the quality, safety, and convenience of transit services in their jurisdictions. This research identified municipal policies and practices that affect public transport providers’ ability to deliver transit services. They were found from a comprehensive literature review, interviews and discussions with five …

Safety Considerations For All Road Users On Edge Lane Roads, Michael Williams, Marcial Lamera, Aleksander Bauranov, Carole Voulgaris, Anurag Pande

Mineta Transportation Institute

Edge lane roads (ELRs), also known as advisory bike lanes or advisory shoulders, are a type of shared street where two-way motor vehicle (MV) traffic shares a single center lane, and edge lanes on either side are preferentially reserved for vulnerable road users (VRUs). This work comprises a literature review, an investigation of ELRs’ operational characteristics and potential road user interactions via simulation, and a study of crash data from existing American and Australian ELRs.

The simulation evaluated the impact of various factors (e.g., speed, volume, directional split, etc.) on ELR operation. Results lay the foundation for a siting criterion. …

Structural Identification And Damage Detection In Bridges Using Wave Method And Uniform Shear Beam Models: A Feasibility Study, Mehran Rahmani, Manan Naik

Mineta Transportation Institute

This report presents a wave method to be used for the structural identification and damage detection of structural components in bridges, e.g., bridge piers. This method has proven to be promising when applied to real structures and large amplitude responses in buildings (e.g., mid-rise and high-rise buildings). This study is the first application of the method to damaged bridge structures. The bridge identification was performed using wave propagation in a simple uniform shear beam model. The method identifies a wave velocity for the structure by fitting an equivalent uniform shear beam model to the impulse response functions of the recorded …

Developing Guidelines For Assessing The Effectiveness Of Intelligent Compaction Technology, Mehran Mazari, Siavash F. Aval, Siddharth M. Satani, David Corona, Joshua Garrido

Mineta Transportation Institute

Many factors affect pavement compaction quality, which can vary. Such variability may result in an additional number of passes required, extended working hours, higher energy consumption, and negative environmental impacts. The use of Intelligent Compaction (IC) technology during construction can improve the quality and longevity of pavement structures while reducing risk for contractors and project owners alike. This study develops guidelines for the implementation of IC in the compaction of pavement layers as well as performing a preliminary life-cycle cost analysis (LCCA) of IC technology compared to the conventional compaction approach. The environmental impacts of the improved construction process were …

Modeling Operational Performance Of Urban Roads With Heterogeneous Traffic Conditions, Swapneel R. Kodupuganti, Sonu Mathew, Srinivas S. Pulugurtha

Mineta Transportation Institute

The rapid growth in population and related demand for travel during the past few decades has had a catalytic effect on traffic congestion, air quality, and safety in many urban areas. Transportation managers and planners have planned for new facilities to cater to the needs of users of alternative modes of transportation (e.g., public transportation, walking, and bicycling) over the next decade. However, there are no widely accepted methods, nor there is enough evidence to justify whether such plans are instrumental in improving mobility of the transportation system. Therefore, this project researches the operational performance of urban roads with heterogeneous …

Characteristics Of Effective Metropolitan Areawide Public Transit: A Comparison Of European, Canadian, And Australian Case Studies, Michelle Derobertis, Christopher E. Ferrell, Richard W. Lee, John M. Eells

Mineta Transportation Institute

This research project investigates the replicable characteristics, policies, and practices of successful metropolitan areawide public transportation networks that contribute to high usage and make transit an effective competitor to the private motor vehicle. The research method involves the qualitative and quantitative analysis of ten international (non-U.S.) case studies. The principal methods employed were web-based research and data collection, as well as telephone interviews with transit agency staff or regional planners as needed. The case studies were limited to developed western countries with similar metropolitan conditions to those in the United States.

This research focuses on key characteristics of highly effective …

Eco-Driving Systems For Connected Automated Vehicles: Multi-Objective Trajectory Optimization, Ke Huang, Xianfeng Yang

Mineta Transportation Institute

This study aims to leverage advances in connected automated vehicle (CAV) technology to design an eco-driving and platooning system that can improve the fuel and operational efficiency of vehicles during freeway driving. Following a two-stage control logic, the proposed algorithm optimizes CAVs’ trajectories with three objectives: travel time minimization, fuel consumption minimization, and traffic safety improvement. The first stage, designed for CAV trajectory planning, is carried out with two optimization models. The second stage, for real-time control purposes, is developed to ensure the operational safety of CAVs. Based on extensive numerical simulations, the results have confirmed the effectiveness of the …

Performance Testing Of Hot Mix Asphalt Containing Biochar, Shadi Saadeh, Yazan Al-Zubi, Basel Zaatarah

Mineta Transportation Institute

In recent years, researchers have been able to identify asphalt binder additives, such as polymers and bio-binder, that can enhance the rheological and mechanical properties of asphalt binders. Earlier studies show that utilizing bio-binder as a partial replacement for asphalt binder has shown promising results in both mechanical and sustainability aspects. Biochar additions improved binder viscosity and low-temperature characteristics. Biochar, which is a byproduct of producing bio-binder, has shown enhanced rheological and mechanical properties when used as an additive to the asphalt binder. In this study, the mechanical properties of asphalt mixtures containing Biochar were investigated. In addition, its color …

Congestion-Clearing Payments To Passengers, Paul Minett, John S. Niles, Richard W. Lee, Brittany Bogue

Mineta Transportation Institute

Peak period motor vehicle traffic volume congests roads all over the world. This project hypothesizes implementing congestion- clearing payments to passengers as a permanent congestion-management solution. Ongoing congestion-free travel would be achieved by removing existing congestion, and absorbing (re)generated demand, at costs that would be expected to increase as the total number of travelers increases over time. The project develops a comprehensive, step-by-step methodology to calculate the benefits and costs of paying for drivers to become passengers at a congestion-clearing level and to maintain this level over time. The method is derived from the literature, analysis by the project team, …

A Multimodal Approach For Monitoring Driving Behavior And Emotions, Arash Tavakoli, Vahid Balali, Arsalan Heydarian

Mineta Transportation Institute

Studies have indicated that emotions can significantly be influenced by environmental factors; these factors can also significantly influence drivers’ emotional state and, accordingly, their driving behavior. Furthermore, as the demand for autonomous vehicles is expected to significantly increase within the next decade, a proper understanding of drivers’/passengers’ emotions, behavior, and preferences will be needed in order to create an acceptable level of trust with humans. This paper proposes a novel semi-automated approach for understanding the effect of environmental factors on drivers’ emotions and behavioral changes through a naturalistic driving study. This setup includes a frontal road and facial camera, a …

Assessing Complete Street Strategies Using Microscopic Traffic Simulation Models, Bernice Liu, Alireza Shams, Jonathan Howard, Serena Alexander, Alex Hughes, Anurag Pande

Mineta Transportation Institute

Authors of this research developed a traffic simulation model for the downtown San Jose network and evaluated five different street redesign and travel demand combinations. This model aids understanding of network-wide effects of changes in street design for local and regional agencies who are interested in implementing complete streets and/or one-way to two-way conversion. The base network may be altered to model and evaluate other complete streets (e.g., road diet) and tactical urbanism (e.g., farmer’s market on city streets on certain days of the week) scenarios. The 3-dimensional animated videos for each scenario are also created to be used for …