NITC Dissertation Fellow Sheida Khademi Uses Modeling to Manage Freeway Capacity

posted on Wednesday, August 4, 2021

We're proud to announce the publication of a new NITC dissertation: "Modeling Capacity: Multiple Weaving Areas," by Sheida Khademi of the University of Texas at Arlington.

"Traffic congestion on freeway systems is one significant concern in urban areas throughout the U.S.A. In this era, building new freeways to reduce congestion is less feasible due to the high capital and social costs. Thus, the effective management and operation of existing freeway facilities has become a preferred approach to reduce traffic congestion. Using the outcomes of this research, agencies can get an idea of which effective variable they should control to manage freeways' multiple weaving areas more efficiently; obtaining the highest capacity while planning for existing freeways. The results will be presented to DOTs and MPOs. The model would be highly useful and money-saving for these agencies, as they prefer to obtain higher capacity by managing existing freeways rather than buying right of ways," Khademi said. 

Systematic, well-designed research provides the most effective approach to the solution of many problems facing highway administrators and engineers. Traffic congestion on freeway systems is one significant concern in urban areas throughout the U.S.A. In this era, building new freeways to...

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Ash Avila, a 2022 TRB Minority Student Fellow, will be a junior this fall in the Sustainable Built Environment undergraduate program at the University of Arizona. She is working with NITC researchers Nicole Iroz-Elardo and Kristina Currans looking at the intersection of transportation and heat as it relates to climate adaptation planning for active travelers. This summer, Ash is working on analyses related to exploring transportation infrastructure and environmental influences of thermal comfort and evaluating some potential mitigations.

Connect with Ash on LinkedIn

Tell us about yourself?

I’m a third year student at the University of Arizona majoring in Sustainable Built Environments with a minor in Spanish. I grew up in a small Southern Arizona border town which led to my interest in urban design, especially in communities with majority Latino populations. In my free time, I work in a small community garden and love to crochet.

What (or who) has influenced your career path in transportation?

Back in my senior year of high school, I became really interested in urban...

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The latest report funded by the National Institute for Transportation and Communities – Transit Impacts on Jobs, People and Real Estate, from the University of Arizona – represents the culmination of nearly a decade of research into the economic effects of transit. To unpack the dense and substantial findings from 17 LRT, 14 BRT, 9 SCT, and 12 CRT systems in 35 metro areas across the United States, we've been telling the story in chapters. Previously we have explored how transit affects real estate rents, the locations of jobs and where people live.

Now we'll dive into the final chapter: Volume 5: Improving Transit...

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Led by Dr. Stephen Fickas of the University of Oregon (UO),  transportation researchers are working to give bicyclists smoother rides by allowing them to communicate with traffic signals via a mobile app. 

The latest report to come out of this multi-project research effort introduces machine-learning algorithms to work with their mobile app FastTrack. Developed and tested in earlier phases of the project, the app allows cyclists to passively communicate with traffic signals along a busy bike corridor in Eugene, Oregon. Researchers hope to eventually make their app available in other cities.

"The overall goal is to give bicyclists a safer and more efficient use of a city’s signaled intersections. The current project attempts to use two deep-learning algorithms, LSTM and 1D CNN, to tackle time-series forecasting. The goal is to predict the next phase of an upcoming, actuated traffic signal given a history of its prior phases in time-series format. We're encouraged by the results," Fickas said.

Their latest work builds on two prior projects, also funded by the National Institute for Transportation a Communities: V2X: Bringing Bikes into the Mix...

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Research demonstrates that marginalized populations experience significant barriers in accessing transit. The Transportation Research and Education Center (TREC) and the Homelessness Research & Action Collaborative (HRAC) at Portland State University are working with the University of Utah in a project funded by the National Institute for Transportation and Communities (NITC) to understand how people from selected historically marginalized communities experience discrimination and harassment on transit and in public areas such as sidewalks, bus stops, and transit platforms when accessing transit.

The study will be conducted in two sites: Portland, Oregon and Salt Lake City, Utah. In Portland, the study population will include racially and ethnically diverse people experiencing homelessness and people who identify as transgender and gender nonconforming; and ride TriMet. In Salt Lake City, the study population will include people experiencing homelessness as well as diverse groups based on their gender, racial, and ethnic identity; who ride Utah Transit Authority. We are seeking transit riders to help inform the study through photos and interviews. Participants will be compensated up to $50 for their labor. The researchers will be recruiting participants for this study through the end of August. 

PARTICIPATION INVOLVES:

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The latest report funded by the National Institute for Transportation and Communities – Transit Impacts on Jobs, People and Real Estate, from the University of Arizona – represents the culmination of nearly a decade of research into the economic effects of transit. To unpack the dense and substantial findings from 17 LRT, 14 BRT, 9 SCT, and 12 CRT systems in 35 metro areas across the United States, we've been telling the story in chapters. Last month we focused on how transit affects where people live, and before that we explored how it impacts the locations of jobs.

This month, we're delving into volume 4 of the final report: Impact on Real Estate Rents with Respect to Transit Station Proximity Considering Type of Real Estate by Transit Mode and Place with...

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In the June 2021 issue of Case Studies on Transport Policy, Ben Clark and Anne Brown of the University of Oregon published an article titled, "What Does Ride-hailing Mean For Parking? Associations Between On-street Parking Occupancy And Ride-hail Trips In Seattle." The paper draws on findings from their NITC research Investigating Effects of TNCs on Parking Demand and Revenues.

Ride-hailing companies, including Uber and Lyft, upset the traditional nexus between driving and parking. As cities consider parking policy reforms amidst a wave of app-based transportation systems, including ride-hailing, the associations between parking occupancy and ride-hailing remain unclear. Examining this association is critical as it may help understand the connections between ride-hailing and the built environment and help cities plan for a future of new transportation technologies that may alter the role of or need for on-street parking. This article examines associations between ride-hail trips and on-street parking occupancy in Seattle, Washington.

The researchers predict that on-street parking occupancy...

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Brandon Siracuse recently earned his master's degree in city and metropolitan planning from the University of Utah. While at the U of Utah he worked as a research assistant, earned a NITC scholarship, and served as an officer in the university's transportation student group, Point B. As of June 2021, he now works as a planner for the City of Council Bluffs, IA. Before enrolling in his master's program, Brandon worked as a full-time intern at the Washington University Medical Center Redevelopment Corporation in St. Louis, where he primarily did GIS work and data analysis to aid in the nonprofit organization's community planning efforts. Brandon is interested in land use, transportation, and the intersection of the two, and is particularly passionate about active transportation.

Connect with Brandon on LinkedIn

Tell us about yourself?

I am originally from Omaha, NE, and I have also had the great privilege of getting to live in St. Louis and Salt Lake City. I got my undergraduate degree in Environmental Science from Saint Louis University, and while I was there I realized I wanted to become an urban planner. I recently graduated from the Master of City and Metropolitan Planning program at the University of Utah, where I served as secretary and then treasurer...

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We're proud to announce the publication of a new NITC dissertation: "Free Movement: Enhancing Open Data To Facilitate Independent Travel For Persons With Disabilities," by Shiloh Deitz of the University of Oregon.

"In this project, I found that across the United States there is a lack of both data for accessible pedestrian routing and tools for filling in those data. AI methods have contributed to filling in missing data for applications like autonomous vehicles but much less often to intervene in quality of life improvements. Critical geoAI, that is, bringing a critical geographic lens to artificial intelligence applications, has the potential to contribute to the amelioration of these data and analytic gaps," Deitz said.

Nearly 40 million Americans report a disability, and of this population, 70 percent travel less because of the challenges they face. When they do travel, those with limited mobility are more likely to be pedestrians or public transit users. Today, free commercial routing applications such as Google Maps offer a robust suite of tools for the able-bodied public to walk, ride bikes, take public transportation, or hail a taxi. Yet, such tools for persons with limited mobility to determine a safe and perhaps even pleasant urban route are experimental, limited, and only available in select cities (e.g....

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We're proud to announce the publication of a new NITC dissertation: "Methodologies to Quantify Transit Performance Metrics at the System-Level," by Travis Glick of Portland State University.

Performance metrics have typically focused at two main scales: a microscopic scale that focuses on specific locations, time-periods, and trips; and, a macroscopic scale that averages metrics over longer times, entire routes, and networks. When applied to entire transit systems, microscopic methodologies often have computational limitations while macroscopic methodologies ascribe artificial uniformity to non-uniform analysis areas. These limitations highlight the need for a middle approach. This dissertation presents a mesoscopic analysis based around timepoint-segments, which are a novel application of an existing system for many transit agencies.

In the United States, fix-route transit is typically defined by a small subset of bus stops along each route, called timepoints. For this research, routes are divided into a consecutive group of bus stops with one timepoint at the center. Each timepoint-segment includes all data collected in that segment during one hour of operation. Visuals for congestion and headway performance, based on the aggregated datasets, are designed to...

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Our multi-year study on automated transit fare collection offers a key finding that won't surprise you: Despite the convenience, the rush toward cashless fare systems has created barriers for lower-income riders seeking to use transit. Results from focus groups, surveys, and a review of current transit agency practices suggest that continuing to accept cash is a crucial way to keep transit accessible. However, dealing with cash has drawbacks: it’s time intensive and expensive. Using a detailed cost-benefit model, the researchers explored the costs for agencies to maintain some cash options and found that some simple approaches can be quite effective. The best bang for the buck? Cash collection on board buses.

Launched in 2019, the research project "Applying an Equity Lens to Automated Payment Solutions for Public Transportation" was supported by a Pooled Fund grant program from the National Institute for Transportation and Communities (NITC) and conducted at three universities: Portland State University (PSU), the University of Oregon (UO), and the University of Tennessee, Knoxville (UTK). The other funding partners were City of Eugene, OR, City of Gresham, OR, Lane Transit District, Clevor Consulting Group, and RTD (Regional Transportation District) Denver....

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