Cars waiting at a traffic signal
Photo by Canetti
Principal Investigator: Gerardo Lafferriere, Portland State University
Learn more about this research by viewing the Executive Summary and the full Final Report on the Project Overview page.

Automobile traffic congestion in urban areas comes with significant economic and social costs for everyone. According to the 2015 Urban Mobility Report, the total additional cost of congestion was $160 billion. As more people move to metropolitan areas, the problems only intensify. The latest NITC report offers a new approach to urban traffic signal control based on network consensus control theory which is computationally efficient, responsive to local congestion, and at the same time has the potential for congestion management at the network level.

Traffic signals represent a significant bottleneck. As cars queue up at a stoplight, then gradually move again once the...

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Pedestrians crossing a street
Principal Investigator: Kelly Clifton, Portland State University
Learn more about this research by viewing the full Final Report on the Project Overview page.

The latest NITC report offers improved tools for pedestrian modeling.

Led by Kelly Clifton of Portland State University, researchers had previously created the the MoPeD pedestrian demand model as well as a pedestrian index of the environment (PIE) for forecasting pedestrian travel. The PIE index improved the sensitivity of walk trip models by incorporating contextual features of the built environment that affect walking behavior in the Portland, Oregon region. Read about Clifton's previous body of work on context-specific modeling.

Useful for academic researchers in transportation, Clifton's research provides a framework for incorporating pedestrian travel behavior forecasts into traditional four-step travel demand models.

Since the method was based on Portland, the next step was to adapt the tools for wider use. In this new report, Clifton and Jaime Orrego-Onate of...

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A red car travels along a highway
Photo by Felix Tchverkin on Unsplash
Principal Investigator: Liming Wang, Portland State University
Learn more about this research by viewing related publications, open-source data, and the full Final Report on the Project Overview page.

The latest report from The National Institute for Transportation & Communities (NITC) offers help to planners seeking to incorporate emerging travel modes—including car sharing, bike sharing, ride hailing, and autonomous vehicles—into regional travel demand models. More specifically, it brings these new travel modes into the Regional Strategic Planning Model (RSPM) tool. As more people start taking advantage of new...

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Sunday, the first day of the Transportation Research Board annual meeting in Washington, D.C., is workshop day. Portland State University doctoral student Tara Goddard presents in a showcase of research stemming from the prestigious Dwight D. Eisenhower Transportation Fellowship program.

Goddard probed the question of why so many bicyclists die in traffic crashes. Cyclists are 12 times more likely to be killed in a crash than a driver or passenger in a car. She wondered what role drivers' attitudes toward cyclists might play.

Goddard's research uses a survey to measure drivers' attitudes and self-reported behaviors and to test drivers' implicit attitudes toward both other drivers and cyclists. She pairs the survey piece with a lab experiment that uses hazard-perception video clips to examine whether drivers notice cyclists. 

By this approach, Goddard hopes to understand drivers' attitudes and whether those attitudes can predict how they act on the road. That understanding can potentially lead to steps to improve cyclist safety. Her workshop runs 9 a.m. to noon in Room 202B of the Walter E. Washington Convention Center.

Disaster recovery workshop

John MacArthur of TREC presents "Smart, Shared and Social: Enhancing All-Hazards Recovery Plans With Demand...

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A new NITC project has developed a robust pedestrian demand estimation tool, the first of its kind in the country.

Using the tool, planners can predict pedestrian trips with spatial acuity.

The research was completed in partnership with Oregon Metro, and will allow Metro to allocate infrastructure based on pedestrian demand in the Portland, Oregon metropolitan area.

In a previous project completed last year as part of the same partnership, the lead investigator, Kelly Clifton, developed a way to collect data about the pedestrian environment on a small, neighborhood scale that made sense for walk trips. For more about how that works, click here to read our news coverage of that project. 

Following the initial project, the next step was to take that micro-level pedestrian data and use it to predict destination choice. For every walk trip generated by the model in the first project, this tool matches it to a likely destination based on traveler characteristics and environmental attributes.

Patrick Singleton, a graduate student researcher at Portland State...

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A new study led by Miguel Figliozzi of Portland State University provides a microscopic evaluation of how two advanced traffic control technologies work together.

Powell Boulevard, an east-west arterial corridor in southeast Portland, Oregon, has been the focus of several research studies by Figliozzi’s TTP research lab. The street is a key route for public transit buses as well as pedestrians and cars, but heavy traffic at peak hours often results in delays.

On Powell there are two systems operating concurrently: a demand-responsive traffic signal system called Sydney Coordinated Adaptive Traffic System (SCATS) and a Transit Signal Priority (TSP) system. The TSP in the Portland metro region is designed to give priority to late buses and to boost transit performance.

In previous studies Figliozzi’s lab has analyzed a multitude of factors on Powell Boulevard including traffic congestion, transit times, air quality and cyclists’ intake of air pollutants, and a before/after evaluation of SCATS.

For this study, the researchers used a novel approach to evaluate how well SCATS and TSP work together by integrating three major data sources and video recordings at individual intersections.

Figliozzi’s team worked closely with TriMet and the City of Portland to...

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OTREC research from Portland State University has developed a new method of travel demand modeling for pedestrian trips.

Transportation professionals use travel demand modeling to forecast how many people will be using a given portion of the transportation infrastructure. This is typically done using a four-step process, the first step of which relies upon a basic unit known as a transportation analysis zone, or TAZ.

A TAZ is a relatively coarse unit of space that can vary in size depending on planners’ needs; typically it encompasses somewhere around 3,000 residents.

Planners started using TAZs in the 1950s, on mainframe computers with limited capabilities, for guidance in making highway investment decisions. As transportation modeling practice has evolved, computers are capable of processing more data and models are being increasingly relied upon to answer more complex questions. 

Despite growing investment in infrastructure that supports active forms of travel, existing modeling tools often poorly represent the nuances of the pedestrian environment. The project’s principal investigator, Kelly Clifton of Portland State University, explores ways to improve upon the modeling tools currently in existence.

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Portland State University engineering doctoral student Alex Bigazzi has developed a new course aimed at giving transportation engineers experience running emissions models. The course, Transportation Emissions Modeling, is offered through the Department of Civil and Environmental Engineering.

The practical nature of the course sets it apart from the few emissions courses offered at other universities, Bigazzi said. “Those tend to be on the policy side or the environmental side,” he said. “This is unique in trying to help engineers more than policymakers or future policymakers.”

The course fits with both Bigazzi’s own experience and Portland State’s faculty research strength in emissions and modeling. The university already offers an air quality course, but Bigazzi’s offering focuses narrowly on emissions from motor vehicles.

Students spent the first half of the inaugural course learning context for the models, including when they are used and what they can do. “There are federal requirements to do these models for all serious transportation projects,” Bigazzi said. “People need to understand what goes into them and how accurate they can be.”

Because emissions models aren’t as complex mathematically as other models, and...

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Portland State University inducted graduate student Kristina Currans into the Denice Dee Denton Women Engineers Hall of Fame in a ceremony Nov. 15. Currans is the second transportation engineering student to win the student award.

Maria Klawe, president of Harvey Mudd College, took the Outstanding Female Engineer honors.

Currans’ boundless enthusiasm and dedication to her work quickly become apparent to anyone who works with her, said Kelly Clifton, an associate professor of civil engineering and director of the Oregon Modeling Collaborative. “I’ve never met someone able to manage so many things,” said Clifton, who nominated Currans for the honor.

Currans works with Clifton as a part of the Oregon Modeling Collaborative and on several OTREC research projects. “She brings a tremendous amount of energy,” Clifton said.

After graduating Oregon State University with a civil engineering bachelor’s degree in 2010, Currans soon made a name for herself in transportation circles. She started her graduate coursework at Portland State and worked during academic breaks with the Oregon Department of Transportation’s Transportation Planning Analysis Unit, home to state and regional transportation models.

“For someone who had just graduated with an undergraduate degree, she completed that internship and really impressed ODOT,” Clifton said. “To do that so quickly caught everyone’s attention.”

Currans tested and worked with the Statewide Integrated...

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With transportation models increasingly used to inform policy decisions at all levels, OTREC is pleased to offer a free educational series designed to help decision makers, transportation officials and others understand these important tools. The series was organized with OTREC’s Oregon Modeling Collaborative and presented during the weekly transportation seminars at Portland State University’s Center for Transportation Studies.

Archived video of the entire eight-week series is now available. Each seminar lasts one hour. Click here for a description of each seminar and links to the video.

While the Friday seminar series has showcased transportation issues for years, the modeling series marks the first time that eight seminars focused on a single theme. Modeling is a timely topic, as policy makers come to rely increasingly on models, whether or not they have a background in modeling.

The series demonstrates how modeling can support better decision-making and explains the tools and the process to a nontechnical audience, said Kelly Clifton, director of the Oregon Modeling Collaborative. Oregon’s discussions regarding modeling tools have helped inform the national discussion, she said.

The final seminar in the series recapped some of the earlier lessons and pointed out some of the...

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