University Transportation Center Research Articles

Framework for the Development of a Diverse Transportation Workforce in the Southeast Region

This project addresses the contemporary challenges faced by the transportation workforce, influenced by demographic shifts, labor market fluctuations, and the growing demand for interdisciplinary skills. Using a case study of the southeastern United States, five main objectives guided the project: a) synthesizing the current state of workforce development practices, b) identifying key challenges in the transportation workforce, c) defining the term “workforce development” within this context, d) exploring potential roles of University Transportation Centers (UTCs) in tackling these challenges, and e) offering actionable recommendations for enhancing transportation workforce development. The research used findings from a literature review, stakeholder meetings, a survey of transportation professionals, and personal interviews with selected experts. The findings were integrated to derive conclusive results instead of independently interpreting each dataset. The study revealed that workforce development hinges on stakeholders, recruitment strategies, educational aspects, and diversity initiatives. The most pressing challenges involved changing labor market trends, demographic shifts, and the necessity for interdisciplinary skills. Workforce development was conceptualized as strategic measures for recruiting, retaining, educating, and training the present and future transportation labor force to meet identified challenges and needs. The UTCs’ potential contributions were identified in facilitating recruitment, inspiring interest in transportation careers, and creating resources for continuous education and training. Key recommendations involve interdisciplinary educational initiatives, specialized training, and resource development to assess and enhance existing training strategies.

Path-Based Formulations for the Design of On-demand Multimodal Transit Systems with Adoption Awareness

This paper reconsiders the On-Demand Multimodal Transit Systems (ODMTS) Design with Adoptions problem (ODMTS-DA) to capture the latent demand in on-demand multimodal transit systems. The ODMTS-DA is a bilevel optimization problem, for which Basciftci and Van Hentenryck proposed an exact combinatorial Benders decomposition. Unfortunately, their proposed algorithm only finds high-quality solutions for medium-sized cities and is not practical for large metropolitan areas. The main contribution of this paper is to propose a new path-based optimization model, called P-Path, to address these computational difficulties. The key idea underlying P-Path is to enumerate two specific sets of paths which capture the essence of the choice model associated with the adoption behavior of riders. With the help of these path sets, the ODMTS-DA can be formulated as a single-level mixed-integer programming model. In addition, the paper presents preprocessing techniques that can reduce the size of the model significantly. P-Path is evaluated on two comprehensive case studies: the midsize transit system of the Ann Arbor – Ypsilanti region in Michigan (which was studied by Basciftci and Van Hentenryck) and the large-scale transit system for the city of Atlanta. The experimental results show that P-Path solves the Michigan ODMTS-DA instances in a few minutes, bringing more than two orders of magnitude improvements compared with the existing approach. For Atlanta, the results show that P-Path can solve large-scale ODMTS-DA instances (about 17 millions variables and 37 millions constraints) optimally in a few hours or in a few days. These results show the tremendous computational benefits of P-Path which provides a scalable approach to the design of on-demand multimodal transit systems with latent demand. History: Accepted by Andrea Lodi, Design & Analysis of Algorithms—Discrete. Funding: This work was partially supported by National Science Foundation Leap-HI [Grant 1854684] and the Tier 1 University Transportation Center (UTC): Transit - Serving Communities Optimally, Responsively, and Efficiently (T-SCORE) from the U.S. Department of Transportation [69A3552047141]. Supplemental Material: The software that supports the findings of this study is available within the paper and its Supplemental Information ( https://pubsonline.informs.org/doi/suppl/10.1287/ijoc.2023.0014 ) as well as from the IJOC GitHub software repository ( https://github.com/INFORMSJoC/2023.0014 ). The complete IJOC Software and Data Repository is available at https://informsjoc.github.io/ .

Experimental Behavior of Precast Bridge Deck Systems with Non-Proprietary UHPC Transverse Field Joints.

Full-depth precast bridge decks are widely used to expedite bridge construction and enhance durability. These deck systems face the challenge that their durability and performance are usually dictated by the effectiveness of their field joints and closure joint materials. Hence, commercial ultra-high performance concrete (UHPC) products have gained popularity for use in such joints because of their superior mechanical properties. However, the proprietary and relatively expensive nature of the robust UHPC mixes may pose some limitations on their future implementation. For these reasons, many research agencies along with state departments of transportation sought their way to develop cheaper non-proprietary UHPC (NP-UHPC) mixes using locally supplied materials. The objective of this study is to demonstrate the full-scale application of the recently developed NP-UHPC mixes at the ABC-UTC (accelerated bridge construction university transportation center) in transverse field joints of precast bridge decks. This study included experimental testing of three full-scale precast bridge deck subassemblies with transverse NP-UHPC field joints under static vertical loading. The test parameters included NP-UHPC mixes with different steel fibers amount, different joint splice details, and joint widths. The results of this study were compared with the results of a similar proprietary UHPC reference specimen. The structural behavior of the test specimens was evaluated in terms of the load versus deflection, reinforcement and concrete strains, and full assessment of the field joint performance. The study showed that the proposed NP-UHPC mixes and field joint details can be efficiently used in the transverse deck field joints with comparable behavior to the proprietary UHPC joints. The study concluded that the proposed systems remained elastic under the target design service and ultimate loads. In addition, the study showed that the use of reinforcement loop splices enhanced the load distribution across the specimen’s cross-section.

Alternative Systems and Materials for Splicing Prestressed-Precast Concrete Piles

The use of piles is a common method for establishing deep foundations for bridges where there is a top layer of weak soil. Among various types of pile and installation methods, driving prestressed-precast concrete piles (PPCP) is a durable and economical option compared with the alternatives. Also, since the method employs pile segments prefabricated in precast plants and delivered to the site for installation, it conforms to the principles of Accelerated Bridge Construction (ABC) and provides a rapid alternative to other methods. However, often because of limitations on shipping and transportation, the length of precast prestressed pile segments that can be delivered to the bridge site has to be reduced. Also, headroom limitations for pile driving may limit the length of pile segments such that establishing adequate resistance may not be achieved with one segment. Therefore, splicing of pile segments has to be performed at the site to produce longer lengths. A study carried out as part of research activities at the Accelerated Bridge Construction University Transportation Center (ABC-UTC) at Florida International University has reviewed various types of available pile splices and attempted to build on the experiences gathered for ABC connections to introduce an alternative configuration for splicing PPCP segments. Accordingly, a variation of grouted bar splice was introduced and designed to provide PPCPs with a time-effective, economical, and labor-friendly method of splicing. The proposed connection is completely new for connecting PPCP segments. Because many of PPCPs are driven in a marine environment, the application of corrosion-resistant material at the splice system is also emphasized. The paper summarizes these investigations. The results of this study show that the newly developed systems can provide the required strength in bending, tension, and compression with smaller sizes and numbers of bars. It also makes the installation faster and easier compared with the current methods.

Mechanical characterization and material variability effects of emerging non-proprietary UHPC mixes for accelerated bridge construction field joints

Accelerated bridge construction (ABC) field joints, e.g. precast deck panels joints, are among the common structural applications of ultra-high performance concrete (UHPC). The higher cost and limited availability of commercial UHPC products have motivated researchers to develop non-proprietary UHPC (NP-UHPC) using locally available materials. One of these efforts is the recent work by the ABC University Transportation Center (ABC-UTC) in the United States to develop NP-UHPC mixes for use in ABC field joints. This paper documents the ABC-UTC mix design and proportions and has two main objectives. First, provide a full material characterization of such mix to allow for future replication and use of this material for different bridge applications as well as modeling purposes. Second, investigate the effect of material sourcing and variability, such as fine aggregate types and particle gradation, on the main mechanical properties of the material. The material characterization tests included flowability, compression, flexure, and direct tensile tests of the NP-UHPC mixes. The results from these tests are then compared with various proposed equations from the literature to verify their validity for use with the considered NP-UHPC mixes.

Non-Destructive Evaluation of Closure Joints in Accelerated Bridge Construction using a Damage Etiology Approach

In accelerated bridge construction (ABC), prefabricated bridge deck elements are merged using “closure joints.” Because of the cast-in-place nature of closure joints that are expected to go into service rapidly and problems observed for some types of closure joints, there have been some concerns about their long-term durability. This has necessitated the need for monitoring the condition of ABC closure joints using non-destructive testing (NDT) methods. Closure joints contain unique features and details that sets them apart from conventional deck panels. This requires a special treatment of closure joints when it comes to selecting the appropriate NDT technique for their health monitoring. A clear guideline for selecting an applicable NDT method for various types of closure joints has not been developed yet. For this purpose, an investigation was carried out in the Accelerated Bridge Construction University Transportation Center (ABC-UTC) at Florida International University. This paper summarizes the result of this investigation. It includes reviews of all relevant NDT methods for applicability to ABC closure joints and efforts for categorizing closure joints according to joint features that affect the use of NDT. Since the applicability of NDT methods heavily depend on the type of expected anomaly to be detected and its root causes, all potential defects and types of damage were identified and investigated using a damage sequence tree (DST). Consequently, damage etiology for ABC closure joints were established using fault tree analysis (FTA). Finally, a quantitative statistical survey was used to substantiate the selection of the NDT methods that were most applicable to the health monitoring of ABC bridges containing closure joints. The results presented in this paper can be used by bridge owners and consultants as an effective and practical guide for the selection of NDT methods for monitoring the health of ABC closure joints.

STEM K-12 Outreach as the Root of Transportation Education: Experiences from the Railway Engineering Field

Demand for graduates with rail transportation expertise remains strong in North America, particularly in engineering and technical fields. Over the past decade, various activities by the American Railway Engineering and Maintenance-of-way Association and rail-focused University Transportation Centers have slowly re-established a railway engineering academic community. Railway courses are now offered at two dozen universities in the United States (U.S.), and, for the first time in decades, several universities offer specific degrees in railway engineering. Despite this progress, challenges remain, such as raising student awareness of rail industry career paths. Since most railway engineering courses are senior-level electives, many students are already committed to other engineering disciplines before they are exposed to railway concepts. To raise student interest in rail courses and satisfy industry demands for internships, students must be introduced to railway concepts before they decide on the direction of their studies. One approach to directing more rail-aware students into engineering programs is rail-themed outreach to K-12 students. Railways still hold a fascination for many young people as complex, multidisciplinary systems, and numerous interesting science, technology, engineering, and math (STEM) concepts can be demonstrated through the lens of railway transportation. Interactive rail-themed classroom activities can illustrate STEM topics while highlighting rail career opportunities and reinforcing railway transportation. This paper reviews rail-themed K-12 STEM outreach activities being undertaken by universities and the strong partnerships between industry and academia required to grow future generations of railway professionals.

Study of Bridge Demolition DOT Survey and Available Standard Specifications

There are many damaged bridges in the United States which are either structurally deficient or functionally obsolete and require replacement or rehabilitation, many using accelerated bridge construction (ABC) techniques. Before a bridge is replaced or rehabilitated, the old structure or component needs to first be demolished. Although the AASHTO LRFD Bridge Design Specification presents minimum bridge design requirements, there is limited information about bridge demolition available for designers and contractors in this field. More study is required to determine best practices in demolition administration and avoid further unintentional events. This study presents the results from a survey prepared and disseminated through a research effort under the Accelerated Bridge Construction University Transportation Center (ABC-UTC). This survey was sent out to all State Departments of Transportation (DOTs). The results of the survey reveal the need for additional guidance in bridge demolition administrations at a national level. According to the results of this study, contractors are the most important part of bridge demolition projects from injuries, fatalities, and responsibility point of view.

A Literature Review and Research Agenda for Understanding and Addressing Pedestrian and Bicycle Safety

Background This paper builds on the research agenda accompanying the university transportation center (UTC) proposal to create the Center for Research on Safe Walking, Active Living, and Cycling (CROSWALC), with a specific focus on the needs of pedestrians and bicyclists including the young, the elderly, and the disabled. Methods As part of a collaborative effort over Spring 2016 to create a University Transportation Center focused solely on pedestrian and bicycle safety, this paper presents a research agenda from researchers spanning engineering, planning, behavior and law enforcement. This paper represents collaboration between colleagues from San Diego State University, University of Wisconsin-Milwaukee, Safe Transportation Research and Education Center (SafeTREC) at the University of California-Berkeley, University of Tennessee, and CSU SLO. This paper also represents feedback and validation from several events at the January 2017 Transportation Research Board conference in Washington DC. Results The resulting research agenda is designed to help both researchers and professionals build a detailed understanding of active travel safety issues and devise innovative yet practical solutions to these issues. The paper focuses on describing key research questions in four related topic areas ( Behavior and Exposure ; Safety Data and Modeling ; Planning, Design and Engineering ; and Innovation and Technology ) all organized under two overarching dimensions designed to help policymakers and practitioners 1) understand the safety problem ( Building Problem Understanding ), and 2) help them devise effective solutions to the safety problem ( Problem Solving ). (For this conference submission we chose the “Additional, specific topic areas” track, as our research agenda combines the two main tracks of the conference related to Problem Understanding and Problem Solving. ) Conclusions The purpose of this paper is to help shape global priorities around safety for pedestrians and cyclists and to guide funding toward improved understanding and targeted solutions for these vulnerable travelers. This paper is motivated and informed by peer-reviewed literature, and draws from the authors’ collective experiences in pedestrian and bicycle safety analysis and problem solving. The four areas presented here are comprehensive and would resonate with most academics and professionals working to both understand pedestrian and bicycle safety issues, and then develop effective solutions. Understanding, promoting, and accommodating walking and cycling is perhaps one of the most critical components of the long-term sustainability, equity, and health of our world’s communities.

A Traffic Light Signal Control System with Truck Priority1*This work has been supported in part by the National Science Foundation under the CPS program and in part by the University Transportation Center METRANS at University of Southern California.

Abstract: This paper proposed and evaluated a traffic light control system for signalized urban intersections that aims to benefit all traffic flows involved by giving priority to trucks. The problem is motivated from the observation that in some cases extending a green traffic signal to have a heavy truck cross an intersection instead of forcing it to stop and restart again may have benefits for all vehicles involved. The proposed traffic light control system uses a co-simulation optimization control approach to generate the traffic light sequence in a network of signalized intersections. The system has been evaluated using a road network simulator adjacent to the twin ports of Long Beach/Los Angeles. The evaluation results show consistent improvements in reducing the overall traffic delays, number of vehicle stops, fuel consumption and vehicle emissions.

The importance of the fundamentals [Future Trends in I&M

Dear Readers, This time, our guest author for the column on Future Trends in IM IEEE Instrumentation and Measurement Society 2012 Outstanding Young Engineer Award; Teaching Commendation for 2012-2013 Academic Year; Outstanding Teaching Award for 2011-2012 Academic Year; the ASNT Fellowship Award for the 2002-2003 and 2006-2007 academic years; the Missouri ST and the Missouri S&T University Transportation Center Graduate Fellowship for 2006. She also received the Materials Evaluation Best Paper Award in 2005 and placed first in the student poster contest at Third International Conference on Electromagnetic Near-Field Characterization and Imaging in 2007. I’m sure you will like her nice contribution.

Development of Enhanced Alaska Pavement Preservation Program and Strategy Selection Guide

The Alaska Department of Transportation and Public Facilities (DOT&PF) wished to enhance its existing pavement preservation management program by using effective pavement preservation treatments for cold regions. This initiative would extend pavement life and defer the need for more costly rehabilitation. By collaborating with the California Pavement Preservation Center and the Alaska University Transportation Center, the Alaska DOT&PF recently completed a pavement preservation research project to improve its pavement preservation program for flexible pavements. Research tasks included conducting an international survey of pavement preservation in cold regions, reviewing literature on cold region pavement preservation treatments, monitoring existing preservation treatments that Alaska used, developing a pavement preservation database, and creating an online computer program for treatment selection. The database for pavement preservation treatment tracking is a web-based online program that includes standard types of pavement preservation strategies used in Alaska; pavement construction, traffic, weather, and other performance-related information; an integrated Google Map function to show the location of pavement preservation projects; and multiple pavement condition survey results with supporting documents. The strategy selection program is integrated within the pavement preservation database. The program sees results of the survey and other information on Alaska treatments to conduct treatment strategy selection and life-cycle cost analysis. Workshops have been given on preservation treatments used in cold regions and use of the database and strategy selection process. Tools developed for the Alaska DOT&PF should be helpful for long-term implementation of an effective pavement preservation program. Other agencies could learn from Alaska's experience.

Engaging New Partners in Transportation Research

Over the past several decades a variety of federal and state programs have invested in transportation research. The U.S. Department of Transportation annually invests approximately $180 million in State Planning and Research (SPR) and university transportation centers (UTCs). This investment generates an extensive portfolio of gray literature (i.e., patents, governmental or scientific research group technical reports, white papers, or preprints) that is not yet uniformly cataloged or accessible, despite the best efforts of the National Technical Information Service, TRB, and the National Transportation Library. This paper reports on a review of the publishing and archiving practices for transportation research technical reports, summarizes best practices, and recommends that UTC and SPR research programs seek and strengthen partnerships with libraries to facilitate the improved production, stewardship, and dissemination of research reports. This paper describes an open access program in Indiana that has digitally archived approximately 1,500 SPR reports dating from 1956, implemented consistent name authority, and created digital object identifiers for reports and data sets to systematically integrate technical reports into scholarly literature. Through new partnerships between the researchers and the home institution, researchers have developed processes to leverage technical report production with the university press to ensure an agile adaptation to emerging digital publishing and open access trends. The adoption of the techniques and the partnerships described in this paper are believed to result in a more efficient investment of state and national transportation research funds by reducing research duplication and demonstrating an improved stewardship of research dollars.

Basic Tool Kit for Estimation of Intermodal Rail Cost

Federal and state transportation planners and others seeking to analyze transportation systems find few publicly available rail analysis models to estimate the operational costs and environmental impacts of rail movements. Moreover, data to populate such models and to test public policy considerations for evaluating public–private partnerships are generally difficult to obtain. This paper, a product of a study funded by Region 6 of the University Transportation Center Program, offers stakeholders the building blocks to develop an integrated rail analysis model capable of testing railway operational and capital investment changes. The paper also reviews the current state of rail modeling, examines selected rail models, and presents the findings of a preliminary intermodal rail costing model developed in the work.

Designing for the Safety of Pedestrians, Cyclists, and Motorists in Urban Environments

Problem: While design solutions aimed at enhancing the safety of pedestrians are viewed as being incompatible with those intended to improve the safety of motorists, there has been little meaningful evaluation of the issue. Instead, this disagreement is based largely on the theoretical assertion that traffic crashes are the result of random driver error, and that the only certain means for addressing safety is to design roadways to be forgiving of these errors when they occur. This perspective overlooks the possibility that crashes may instead be the product of systematic patterns of behavior associated with the characteristics of the built environment. Purpose: This study sought to discover whether urban crash incidence is the product of random error, or whether it may be influenced by characteristics of the built environment. Methods: We used negative binomial regression models to examine the relationship between several aspects of the built environment and the incidence of crashes involving motorists, pedestrians, and cyclists. We further subdivided motorist crashes into multiple-vehicle, fixed-object, and parked-car crashes to determine if these crash types had unique characteristics. Results and conclusions: We used vehicle miles of travel as a proxy for random error and found it to be positively, but weakly, associated with crashes involving motorists and pedestrians. We found stronger associations between crashes and characteristics of the built environment. We found miles of arterial roadways and numbers of four-leg intersections, strip commercial uses, and big box stores to be major crash risk factors, while pedestrian-scaled retail uses were associated with lower crash incidences. The results suggest that improvements to urban traffic safety require that designers balance the inherent tension between safety and traffic conflicts, rather than simply designing roadways to be forgiving. Takeaway for practice: Most of the ongoing debate between pedestrian advocates and traffic engineers has focused on the relative desirability of designing urban roadways to be forgiving to random driver error. Such debates have led both groups to ignore the more salient issue of systematic error. This study finds that the factors associated with a vehicle crashing into a pedestrian and cyclist are largely the same as those resulting in a crash with another vehicle. Designs that balance the inherent tension between vehicle speeds and traffic conflicts can be used to enhance the safety of pedestrians, cyclists, and motorists alike. Research support: This research was sponsored by the Southwest University Transportation Center.

Seat Belt Use on Alabama School Buses

The Alabama State Department of Education commissioned a study of school bus seat belt use on the basis of 12 buses (less than 1% of the fleet) equipped with seat belts and digital camera systems. The initial year of the study established baseline rates for normal situations. About 64,000 pupil observations were gathered from 11 buses on Tuesday through Thursday afternoon routes and from one control bus on Monday through Friday morning and afternoon routes. Afternoon route seat belt use was estimated to be 65.9% on the basis of 44,000 of the observations made. Given the small sample size, this value should be considered representative of the fleet but not exact. Belt use varied widely from bus to bus (94.5% to 4.8%). The degree of scatter was confirmed by large values of the coefficient of variation. Trends were documented for variation by day of week, morning versus afternoon, time on route, effects of bus aides, and changes in use over the school year. The findings confirmed the opinions of national experts and Alabama pupil transportation managers. High seat backs blocked the view of drivers as they tried to control pupil conduct and enforce seat belt use. The researchers of the University Transportation Center for Alabama examined digital images of pupils on the buses, but they could determine whether a seat belt was used only 65% of the time. While driving, bus drivers are able to see far fewer pupils: it is unrealistic to expect the drivers to enforce seat belt use.

Safe Urban Form: Revisiting the Relationship Between Community Design and Traffic Safety

Problem: While concerns about traffic safety were central to the development of conventional community design practice, there has been little empirical examination of the relationship between community design and the incidence of traffic-related crashes, injuries, and deaths. Purpose: We examine the relationship between community design and crash incidence. Methods: We present a brief historical review of the safety considerations that helped shape conventional community design practice and then analyze GIS data on crash incidence and urban form using negative binomial models. Results and conclusions: We find that many of the safety assumptions embedded in contemporary community design practice are not substantiated by the empirical evidence. While disconnecting local street networks and relocating nonresidential uses to arterial thoroughfares can reduce neighborhood traffic volumes, this does not appear to improve safety, but rather substitutes one set of safety problems for another. We found urban arterials, arterial-oriented commercial developments, and big box stores to be associated with increased incidences of traffic-related crashes and injuries, while higher-density communities with more traditional, pedestrian-scaled retail configurations were associated with fewer crashes. We found intersections to have mixed effects on crash incidence. We conclude by discussing the likely reasons for these findings (vehicle operating speeds and systematic design error) and outline three community design strategies that may help improve traffic safety. Takeaway for practice: Community design is strongly associated with crash incidence. The speed and operating characteristics of arterial thoroughfares, as well as the design and configuration of commercial and retail uses, appear to be particularly important. Our findings suggest that safety may be enhanced by strictly managing access along arterial thoroughfares and by locating commercial and retail uses away from these roadways, or at least orienting them toward lower-speed access lanes with limited connections to the arterial system. Designing communities to have higher-density, more urban design configurations generally appears to help reduce crash incidence, although four-leg intersections pose potential traffic hazards. Research support: This research was sponsored by the Southwest University Transportation Center (SWUTC).

Demographics, Destiny, and Anticipating the Future of the Transportation System

The United States' demographic profile is changing. Tomorrow's America will be older, more ethnically and culturally diverse, experience more immigration both internally and internationally, and have a new generation of better educated women. How will these potentially disruptive demographics affect the future of the transportation system? This article outlines the objectives of a U.S. Department of Transportation, Research and Innovative Technology Administration's University Transportation Centers Program's Spotlight Conference on the Impact of Changing Demographics on the Transportation System, held at the National Academies, Washington, DC, October 2008. Seven of the several papers presented are published here as a special issue to identify key research questions and implications for both policy and practice.

Transportation Asset Management Overview

This article defines Transportation Asset Management (TAM) as a systematic process of operating, maintaining, and upgrading physical assets cost-effectively. TAM combines engineering and mathematical analyses with sound business practice and economic theory. State efforts to adopt TAM include Michigan’s TAM Council and Indiana’s Highway Asset Management System software program. This article also describes research initiatives sponsored by the National Cooperative Highway Research Program, the Midwest Regional University Transportation Center, and private sector firms. Finally, this article summarizes the main articles in this focus issue.

THE KANSAS UNIVERSITY TRANSPORTATION CENTER (KUTC): Its Societal Roles

Universities are an integral part of society, and they have a role in society. In addition to educate the youngs, many universities also conduct research and service activities. In this paper, a brief description of a university-based research unit, University of Kansas Transportation Center (KUTC) is presented. Three KUTC research/service programs namely the LTAP, the RTAP and the PC-TRANS are discussed in detail. The activities involved in these programs are outlined. These research/service programs have been able to reach and impact a large group of professionals in the field. The programs have contributed significantly to the betterment of our transportation system and the transportation community.