Civil and Environmental Engineering Commons^™

Dynamic Impact Testing And Numerical Analysis Of Non-Proprietary Astm F2656-20 M50 Anti-Ram Barrier Components, Weston Kelley

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

In a post-9/11 world, hostile actors are using vehicles as weapons to inflict civilian casualties. Pedestrians, vulnerable road users, military personnel, and police may be targeted using a vehicle as a weapon. The United States Department of Defense (DoD) also utilizes Entry Control Facilities (ECFs) which are carefully designed transportation corridors to manage how threat vehicles are able to access military facilities. In 2004, DoD started to upgrade all ECFs using both passive and active barriers. Many anti-ram vehicle barriers were evaluated according to the criteria established in ASTM F2656, but to date few options are available which are (1) …

Impervious Surfaces From High Resolution Aerial Imagery: Cities In Fresno County, Yushin Ahn, Richard Poythress

Mineta Transportation Institute

This study investigates impervious surfaces — areas covered by materials with restricted water permeability, such as pavement, sidewalks, and parking lots—due to their crucial role in influencing water dynamics within urban landscapes. The impermeability of these surfaces disrupts natural water absorption processes, resulting in adverse environmental consequences such as increased flooding, erosion, and water pollution. The research employs impervious surface analysis, a method involving the mapping and analysis of these surfaces within specified study areas, including cities, counties, and census tracts. Remote sensing techniques, specifically satellites and aerial imagery, are commonly utilized for the identification and classification of impervious surfaces. …

Does California High-Speed Rail Promote Accessibility For Station Cities?: Case Study Of Fresno And Merced, Chih-Hao Wang, Na Chen

Mineta Transportation Institute

California High-Speed Rail (CHSR) will largely change transportation cost across the state after it starts operating. Past studies show that only Fresno and Merced among station cities in the Central Valley would attract more future activities with the CHSR. The establishment of active CHSR also implies a new daily living sphere for all the station cities, and, therefore, accessibility to work and residential amenities should be reviewed to inform planners of future land-use and transportation developments. A research framework has been developed better to understand the impact of CHSR on job and amenity accessibility by driving, transit, and walking in …

Safety Evaluation Of Hawaii Dot Modified Type A-1 Flared Buried In Backslope Guardrail End Terminal, Sina Changizian

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

The Hawaii Department of Transportation (HDOT) desired to evaluate the crashworthiness of a guardrail end terminal design in which the upstream guardrail anchorage was connected to a block partially buried in a cut slope, known as a “Buried in Backslope” or BIB design. The HDOT BIB system used an upper W-beam with 8-in. deep blockouts attached to W6x9 steel posts and a lower W-beam rubrail located 3 in. below the upper rail. The system used two horizontal flares: 7.4:1 near the upstream anchor block and a 13:1 flare through the ditch.

Critical impact points (CIPs) were identified and recommended for …

Beneath I-280: Excavating A Neighborhood Lost To San José Freeways, Leila Ullmann, Gordon Douglas

Mineta Transportation Institute

Throughout the 1960s and 1970s, thousands of people in San José, California were displaced from their homes as the state used eminent domain to purchase land and uproot neighborhoods for the construction of Interstate freeways. This report presents a multifaceted research and public knowledge effort that uncovers some of the communities buried beneath these freeways, in the area where I-280 and CA-87 meet today near downtown San José. The project builds primarily from previously unprocessed California Department of Transportation (CalTrans) archival documents, which this project studies for the first time. The records are rich in detail about valuation and sale …

Data From: Active Transportation Counts From Existing On-Street Signal And Detection Infrastructure, Sirisha Kothuri, Patrick Allen Singleton, Mahyar Vahedi Saheli, Elizabeth Yates, Joseph P. Broach

Civil and Environmental Engineering Faculty Datasets

This study’s objective was to use data from existing traffic signal infrastructure to estimate pedestrian volumes. Pedestrian push-button actuations were collected from signal controller logs at 49 intersections in western Oregon and an additional 16 intersections in eastern Oregon. These actuations were then compared to observed pedestrian counts, totaling over 34,000 people, obtained from video recordings. After exploring various options, a simple quadratic relationship was modeled using a single measure of pedestrian signal activity: the number of push-button presses (filtered to remove multiple presses within 15 seconds). The model’s predictions showed a correlation of 0.86 with observed pedestrian volumes and …

Characterization Of Recent Wild Pig‑Vehicle Collisions In Georgia, Usa, Jeremiah L. Psiropoulos, Emily Howe, John J. Mayer, Sophie C. Mckee

USDA Wildlife Services: Staff Publications

Vehicle collisions with wild pigs (Sus scrofa) are reported almost everywhere this species is found. However, this is one of the least studied and characterized forms of damage that these invasive animals cause in the United States (US). We analyzed 518 wild pig-vehicle collisions (WPVCs) that took place statewide in Georgia between 2015 and 2021. From that dataset, we analyzed several parameters in order to better understand and characterize these accidents on a scale that had previously not been done in the US. Wild pig-vehicle collisions were reported from 105 out of the 159 counties in Georgia, increasing …

Policy Brief: Evaluation Of The Safety Of Pedestrian Crossing Treatments In Small And Rural Communities, Parsa Pezeshknejad, Dana Rowangould, James Sullivan

University of Vermont Transportation Research Center

TRC Policy Brief: Rural areas often lack adequate pedestrian infrastructure, resulting in elevated safety risks for pedestrians. The combination of higher speed limits and reduced driver awareness amplifies the potential for pedestrian collisions when crossing the roadway.

This study addresses uncertainty about the effectiveness of rectangular rapid flashing beacons (RRFBs) and LED-embedded signs (LESs) as potential safety interventions. RRFBs and LESs are both pedestrian crossing treatments that allow pedestrians to activate lights to alert drivers of their intent to cross. RRFBs include horizontal LED lights mounted to the sign pole, while LESs include LEDs embedded in the edge of the …

A Practical Framework For Component-Level Structural Health Monitoring Of The Gerald Desmond Bridge, Mehran Rahmani, Vesna Terzic, Andrea Calabrese, Brittany Cambell

Mineta Transportation Institute

Bridges serve as critical transportation infrastructure, but traditional maintenance inspection to ensure their safety is time-consuming, costly, and labor-intensive, especially for larger and more complex structures. This study presents a practical framework for the instrumentation, data acquisition, and remote condition assessment of the Gerald Desmond Bridge, California’s largest cable-stayed bridge. The framework aims to establish a foundation for real-time or near real-time remote health monitoring of the bridge’s critical elements. The study highlights the advantages of remote monitoring in terms of efficiency, cost-effectiveness, and early detection of damage.

Fiber-Based Seismic Damage And Collapse Assessment Of Reinforced Concrete Single-Column Pier-Supported Bridges Using Damage Indices, Yu-Fu Ko, Jessica Gonzalez

Mineta Transportation Institute

Near-fault earthquakes can have major effects on transportation systems due to the structural damage they impose on bridges. Therefore, it is imperative to assess the seismic damage of bridges appropriately, and this research focuses on reinforced concrete (RC) bridges. This research advances the seismic performance assessment of RC single-column pier-supported bridges with flexural failure under near-fault ground motion by use of ductility coefficients and damage indices. The methodology included modeling fiber-based nonlinear beam-column elements to simulate the damage development process of RC bridge piers under earthquake loadings, considering the global buckling of longitudinal steel bars, examining the cracking and spalling …

System-Of-Systems Integration For Civil Infrastructures Resiliency Toward Multihazard Events, Vahid Balali

Mineta Transportation Institute

Civil infrastructure systems—facilities that supply principal services, such as electricity, water, transportation, etc., to a community—are the backbone of modern society. These systems are frequently subject to multi-hazard events, such as earthquakes. The poor resiliency of these infrastructures results in many human casualties and significant economic losses every year. An outline of a holistic view that considers how different civil infrastructure systems operate independently and how they interact and communicate with each other is required to have a resilient infrastructure system. More specifically a systems engineering approach is required to enable infrastructure to remain resilient in the case of extreme …

Extending The Service-Life Of Bridges Using Sustainable And Resilient Abutment Systems: An Experimental Approach To Electrochemical Characterization Of Lightweight Mechanically Stabilized Earth, Fariborz M. Tehrani, Kenneth L. Fishman, Farmehr M. Dehkordi

Mineta Transportation Institute

Bridges are critical components of transportation infrastructure. This research addresses the need to extend the service life of bridges by improving the safety and reliability of bridge abutments and reducing their life-cycle cost and footprints. Mechanically stabilized earth (MSE) is a known strategy to enhance the economy and performance of bridge abutments. In addition, the application of rotary-kiln-manufactured lightweight aggregate backfills improves the performance of MSE bridge abutments with a leaner structural system. Such improvements include a reduction of structural demands due to a lower density, free drainage of granular materials, a high internal friction angle, less settlement with no …

Pavement Condition Survey Using Drone Technology, Lerose Lane, Dingxin Cheng

Mineta Transportation Institute

Timely repairs of pavement defects are essential in protecting both public road and highway systems. Identification of pavement distresses is necessary for planning pavement repairs. This has previously been performed by engineers surveying the roadways visually in the field. As drone usage has progressed, it has become clear that drones are a valuable tool to enhance visual documentation, improve project communication, and provide various data for processing. The use of drone technology has improved both the speed and accuracy of capturing data. Available software has allowed the data to be processed and analyzed in an office environment. This report summarizes …

Traffic Safety Toolbox - Addressing Speeds: Final Report, James Sullivan, Dana Rowangould

University of Vermont Transportation Research Center

Reducing speeding and aggressive driving is one of seven critical emphasis areas identified in the Vermont Highway Safety Plan, which targets reductions in major crashes on Vermont highways. Vermont towns recognize the need to discourage speeding and implement countermeasures that will bring speeds down to posted speed limits, especially in transition zones from high-speed rural highways to low-speed village streets. Vermont’s villages and towns often lack the resources and capacity needed to select and implement speeding countermeasures that will be effective and appropriate for a particular context. There is a need for targeted, digestible guidance to assist these municipalities. This …

Smart Transportation In Small- And Medium-Sized Cities In Central California, Hongwei Dong

Mineta Transportation Institute

The research on smart transportation in the United States has centered on large metropolitan areas. The adoption of smart transportation technologies in small-and medium-sized cities outside of large metropolitan areas is less studied and understood. This study examined the adoption of smart transportation technologies in small-and medium-sized cities in Central California. The analysis was based on the online survey responses from 29 transportation officials and professionals who worked for 18 municipal government departments and six metropolitan planning organizations (MPOs) in Central California as well as in depth semi-structured interviews with seven of them. The study showed that smart transportation in …

Experimental Investigation Of The Self-Healing Potential Of Bacteria For Sustainable Concrete Structures, Pitiporn Asvapathanagul, Simone Galano, Andrea Calabrese, Mehran Rahmani, Maggie Ly, Daniela Flores, Michael Hernandez, Nicholas Banuelos

Mineta Transportation Institute

Although concrete is the most widely used building material in the world, its limited tensile strength makes cracking a common phenomenon in concrete elements. This study investigates the potential of autonomous self-healing as an eco-friendly and lowcost method to increase the durability of concrete. The crack-healing potential of different types of high-alkaline-tolerant bacteria or calcite-precipitation microorganisms is investigated. High-alkaline-tolerant bacteria and calcite-precipitation microorganisms were used to retrofit lab-fractured concrete samples. The samples healed with each of these bacteria groups were cast and tested under compressive load up to failure to measure the compressive strength of the concrete samples. The outcomes …

Preconstruction Support Cost Hours Estimating On Caltrans Pavement Rehabilitation Projects, Nigel Blampied, Tariq Shehab, Elhami Nasr, Laxmi Sindhu Samudrala

Mineta Transportation Institute

Because the construction phase accounts for the majority of project costs for pavement rehabilitation projects, most research on infrastructure project cost estimating focuses on that phase, rather than on the preconstruction phases. Nevertheless, costs incurred prior to construction, referred to in this report as "preconstruction costs" are significant and worthy of consideration (See Section 2.1 of the report for a more detailed and precise definition of preconstruction). In the 20202021 fiscal year, for instance, the California Department of Transportation (Caltrans) spent more than $169 million on preconstruction work for pavement rehabilitation projects. This report presents the results of a study …

Modeling And Evaluating Alternatives To Enhance Access To An Airport And Meet Future Expansion Needs, Srinivas S. Pulugurtha, Abimbola Ogungbire, Chirag Akbari

Mineta Transportation Institute

The continued growth of air travel calls for the incessant construction effort at many airports and their surroundings. Thus, there is a need to determine how airports can better manage existing infrastructure to accommodate this growth. This study, therefore, focuses on (1) investigating how changes in transportation infrastructure have affected travel time reliability (TTR) of the surrounding road network within the airport vicinity over time, and, (2) exploring selected unconventional intersection designs and proposing new inbound/outbound access routes from the nearby major roads to the airport. The efficiency of road networks that surrounds large airports is discussed using Charlotte Douglas …

Using Thermal Remote Sensing To Quantify Impact Of Traffic On Urban Heat Islands During Covid, My-Thu Tran, Bo Yang

Mineta Transportation Institute

A three-month lockdown in the U.S. at the beginning of the COVID-19 outbreak in 2020 greatly reduced the traffic volume in many cities, especially large metropolitan areas such as the San Francisco Bay Area. This research explores the impact of transportation on climate change by using remote sensing technology and statistical analysis during the COVID-19 lockdown. Using thermal satellite data, this research measures the intensity of the urban heat island, the main driver for climate change during the urbanization process. The research team acquired morning and afternoon MODIS data in the same periods in 2019 before the pandemic and 2020 …

Effectiveness Of Rectangular Rapid Flashing Beacons (Rrfbs) In Small And Rural Communities, Dana Rowangould, James Sullivan, Parsa Pezeshknejad

University of Vermont Transportation Research Center

Ensuring the safety of pedestrians and cyclists in rural and small communities is becoming increasingly important as planners seek to encourage active travel and eliminate traffic-related injuries and fatalities, consistent with Vision Zero. One area of focus is the protection of vulnerable road users such as pedestrians, who face a significant risk of injury or death in a traffic collision. The risks to pedestrians are particularly high when crossing roadways in high-risk areas such as high-speed and low pedestrian-volume rural roads and between intersections where drivers may not expect them. One concern in rural communities is that pedestrians may face …

Evaluating Automated Truck Platoon (Atp) Deployment For The Los Angeles–Inland Empire Trade Corridor Enhancement, Shailesh Chandra, Aastha Chaudhary, Prakhar Srivastava, Jose Torres-Aguilera

Mineta Transportation Institute

The California Freight Mobility Plan 2020 lists the Los Angeles-Inland Empire trade corridor region as a prominent industrial hub experiencing an increase in freight flows. The California Freight Mobility Plan also regards automated truck platoon (ATP) as an emerging opportunity to minimize congestion on the trade corridor routes. Percentage change in accessibility from 2022 (“without” ATP) to 2040 (“with” ATP) is calculated for the eighteen industry sectors of the Los Angeles-Inland Empire trade corridor. The application of the accessibility formulation was carried out with data on travel time from I-710 and I-10 within Los Angeles County. The findings suggest that …

Evaluation, Comparison, And Improvement Recommendations For Caltrans Financial Programming Processes And Tools, Wenbin Wei, Nigel Blampied, Raajmaathangi Sreevijay

Mineta Transportation Institute

The California Transportation Improvement Program System (CTIPS) is the main tool used by Caltrans’ Division of Financial Programming to support the business of transportation programming. It is a multi-agency joint-use project programming database system applied to develop and manage various state and federal transportation programming documents. The goal of this project is to evaluate CTIPS and explore various new options that will maintain the current functionality of CTIPS, meet legislative guidelines for ADA compliance, ensure security of the system, and have sufficient scalability and capabilities for integration with other systems in the future. The research is based on the review …

Analysis Of Traffic Conflicts With Right Turning Vehicles At Unsignalized Intersections In Suburban Areas, Abbas Sheykhfard, Farshidreza Haghighi, Sarah Bakhtiari, Sara Moridpour, Kun Xie, Grigorios Fountas

Civil & Environmental Engineering Faculty Publications

Right-turn collisions at intersections are one of the most dominant crash types in suburban areas, especially at unsignalized intersections. There is, however, a lack of comprehensive research on the speed patterns of vehicles during right-turn manoeuvres and their impact on crashes. To provide an in-depth investigation of the factors determining the safety of right-turn manoeuvres, driving behaviour data were collected through an instrumented vehicle study. Using this data, binary logistic regression models were developed to identify the factors affecting the probability of Vehicle-Vehicle (V-V) and Vehicle-Pedestrian (V-P) conflicts at six suburban intersections in Babol, Iran, during right-turn stage manoeuvres. In …

The Role Of Information And Education On Modifying Support For Gas Tax Alternatives Using An Informed Choice Questionnaire, Clare Nelson, Gregory Rowangould

University of Vermont Transportation Research Center

In the United States, transportation fuel excise taxes commonly referred to as the “gas tax” provide a large share of funding to state agencies for transportation maintenance and construction projects. The revenue generating capacity of the gas tax is threatened by increasing vehicle fuel efficiency, electric vehicles adoption and inflation. Alternative funding schemes are necessary, but public acceptance of tax changes is low. We surveyed residents of Vermont, Maine, and New Hampshire to gauge understanding of and support for a mileage-based user fee and a flat fee as potential replacements for the current gas tax and the potential to modify …

Traffic Safety Toolbox: Speeding Countermeasures Toolbox For Vermont, James Sullivan, Dana Rowangould, Erica Quallen, Danica Dytioco

University of Vermont Transportation Research Center

Reducing vehicle speeds is an important strategy for reducing the risk and severity of collisions and ensuring the safety of drivers, pedestrians, and cyclists, especially in transition zones, where rural highways with higher posted speeds (typically 50 mph) enter a village or town center. This Traffic Safety Toolbox (“Toolbox”) of speeding countermeasures is intended for use by Vermont towns with posted speeds that are not widely adhered to by drivers, whether in a transition zone entering a village or town center (roads with speed limits of 35 mph and above and functional classifications of 3 or 4), or within the …

Are Ride-Hailing Services Safer Than Taxis? A Multivariate Spatial Approach With Accomodation Of Exposure Uncertainty, Guocong Zhai, Kun Xie, Hong Yang, Di Yang

Civil & Environmental Engineering Faculty Publications

Despite many research efforts on ride-hailing services and taxis, limited studies have compared the safety performance of the two modes. A major challenge is the need for reliable mode-specific exposure data to model their safety outcomes. Moreover, crash frequencies of the two modes by injury severities tend to be spatially and inherently correlated. To fully address these issues, this study proposes a novel multivariate conditional autoregressive model considering measurement errors in mode-specific exposures (MVCARME). More specially, a classical measurement error structure is used to accommodate the uncertainty of mode-specific exposures estimated, and a multivariate spatial specification is adopted to capture …

Evaluation Of Nanoclay Additives For Improving Resistance To Moisture Damage In Hot Mix Asphalt (Hma), Amro El Badawy, Ashraf Rahim

Mineta Transportation Institute

Transportation has an enormous impact on the U.S. economy and on the lives of all Americans. Many modes of transportation rely on pavement, but pavement conditions deteriorate over time because of the combined effects of traffic and climate. Exposure to moisture often causes premature failure of asphalt pavements as it reduces the stiffness of the asphalt and enables stripping of the asphalt from the aggregate. This research evaluates the effectiveness of clay nanomaterials (i.e., nanoclays) in improving the resistance of hot mix asphalt (HMA) to moisture damage and compares the enhancement results to anti-stripping additives commonly used in pavement construction. …

Evaluation Of Left Shoulder As Part-Time Travel Lane Design Alternatives And Transportation Management Center Staff Training Module Development, Zhuohang Deng, Zhiliang Luo, Neil Hockaday, Ahmed Farid, Anurag Pande

Mineta Transportation Institute

Permanent capacity expansion, such as adding new lanes, is no longer a viable strategy to address traffic congestion in California; hence, ITS (Intelligent Transportation System) strategies, such as part-time use of the shoulder as a travel lane, need to be explored. The use of the shoulder as a travel lane during peak traffic hours has limited applications in the US, and most use the right shoulder as a part-time travel lane even though either the right or left shoulder (but not both) may be used. Caltrans District 5 is exploring the use of Left Shoulder as a Part-time Travel Lane …

Effect Of Weather Events On Travel Time Reliability And Crash Occurrence, Sonu Mathew, Srinivas S. Pulugurtha

Mineta Transportation Institute

The magnitude of the effect of adverse weather conditions on road operational performance varies with the type of weather condition and the road characteristics of the road links and adjacent links. Therefore, the relationship between weather and traffic is always a concern to traffic engineers and planners, and they have extensively explored ways to integrate weather information into transportation systems. Understanding the influence of weather on operational performance and safety helps traffic engineers and planners to proactively plan and manage transportation systems. The main objective of this research is to evaluate the effect of adverse weather conditions on travel time …

Does Transit Service Reliability Influence Ridership?, Srinivas S. Pulugurtha, Raunak Mishra, Sravya L. Jayanthi

Mineta Transportation Institute

This research focused on analyzing the association between transit service reliability indicators and ridership. Further, the effect of road network, demographic, socioeconomic, and land use characteristics on transit service reliability was analyzed. The analysis was conducted at a bus stop level. Bus arrival/departure and ridership data from the Charlotte Area Transit System (CATS) was obtained. The road network, demographic, socioeconomic, and land use characteristics were captured within 0.25-mile and 0.50-mile buffers. Pearson correlation analysis was conducted to understand the association between road network, demographic, socioeconomic, and land use characteristics and bus transit service reliability measures. The results show that bus …