Travel time reliability – or the consistency and dependability of travel times from day to day, and at different times of day – is a key metric that significantly affects people’s travel behavior. Since businesses rely heavily on transportation systems, an unreliable transportation network can also impact the economic competitiveness of urban areas. As such, reliable travel times are important for transportation agencies to promote economic stability within a community. Having accurate methods to evaluate reliability is important for both transportation practitioners and researchers.

A new report from Portland State University offers an improved method for determining the confidence interval of travel time reliability metrics. Researchers Avinash Unnikrishnan, Subhash Kochar and Miguel Figliozzi of PSU’s Maseeh College of Engineering and Computer Science used a highway corridor in Portland, Oregon as a case study to evaluate their method, and found that it compared favorably with other methods of evaluating the confidence interval of travel time reliability metrics.

"Traffic engineers can apply this method to come up with a range of estimates for the unknown true travel time reliability metric. The travel time reliability metrics calculated by traffic engineers and transportation planners will have variability due to factors such as road...

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How can community members become more engaged in transportation decision making?

Individuals and groups can learn to effect powerful change, but success requires some familiarity with how civic processes work. Community Transportation Academies, or CTAs, provide a basic technical understanding of how a city or region’s transportation system operates, along with the decision makers and decision-making processes that determine how the system is shaped.

Supported by the National Institute for Transportation and Communities (NITC), the new Wasatch Transportation Academy (WTA) at the University of Utah was piloted in 2022 in the Salt Lake City region. The research team developed a course vision, topics, and logistics for the WTA by interviewing stakeholders in the Utah Governor’s Office of Planning and Budget, the Utah Department of Transportation, the Utah Transit Authority, Salt Lake County, Salt Lake City, and the Wasatch Front Regional Council. Led by Nathan McNeil of Portland State University and Keith Bartholomew of the University of Utah, the WTA used the established Portland Traffic and Transportation class in Portland, Oregon as a framework. 

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The Transportation Undergraduate Research Fellowship (TURF) program at Portland State University has hosted twenty-four fellows since 2017, and recently wrapped up its summer 2022 session. This year, six undergraduate researchers worked on projects aimed at improving the safety and efficiency of multimodal transportation systems. The research goals ranged from surveying pedestrian count programs and safety performance functions across the country, to reviewing case studies of tactical curb extensions and collecting pedestrian data at intersections. 

Hosted by PSU’s Transportation Research and Education Center (TREC), the TURF fellows also experience a variety of workshops with PSU faculty and staff on research, communication and data science skills. They attended the 2022 Forth Mobility Roadmap Conference in June, and participated in networking events with the Portland chapters of YPT and WTS. Here is some of what the students had to say about the experience:

"I enjoyed all of the experiences surrounding my time here at TREC, but I loved the workshops. I especially enjoyed Dr. Golub's workshop...

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Researchers Aaron Golub, John MacArthur and Sangwan Lee of Portland State University, Anne Brown of the University of Oregon, and Candace Brakewood and Abubakr Ziedan of the University of Tennessee, Knoxville have published a new journal article in the September 2022 volume of Transportation Research: Interdisciplinary Perspectives

Rapidly-evolving payment technologies have motivated public transit agencies in the United States to adopt new fare payment systems, including mobile ticketing applications. The article, "Equity and exclusion issues in cashless fare payment systems for public transportation," explores the challenges facing transit riders in the U.S. who lack access to bank accounts or smartphones, and potential solutions to ensure that a transition to cashless transit fares does not exclude riders. Learn more about the project and read an open-access version of the final report.

The study asks: who is most at risk of being excluded by the transition to new fare payment systems and how would riders pay transit fares if cash payment options were reduced or eliminated? Researchers answer these questions using intercept surveys of 2,303 transit riders in Portland-Gresham, OR, Eugene, OR, and Denver, CO.

The...

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In order to make sure bicyclists' needs are considered when improving a transportation system, planners and engineers need to know how many people are biking, and where. 

Traditional bicycle counters can provide data for limited sections of the bike network; often these counters are installed at important locations like trails or bridges. While limited in location, they count everyone who bikes by. Meanwhile, GPS & mobile data cover the entire transportation network, but that data only represents those travelers who are using smartphones or GPS. Combining the traditional location-based data sources with this new, crowdsourced data could offer better accuracy than any could provide alone. 

"Knowing how many people are bicycling on a street is really important for a number of reasons. As just a few examples, bicycle volumes give you a way to understand safety data and determine crash rates. They provide insight into where and how bicycle trips are taking place, which can help plan for new or improved facilities," said Nathan McNeil of Portland State University.

Supported by a pooled fund grant administered by the National Institute for Transportation and Communities (NITC), Dr. Sirisha Kothuri of Portland State University led a research project aimed at fusing traditional and...

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Nick Puczkowskyj is a graduate research and teaching assistant at Portland State University's College of Urban and Public Affairs. He is a current Urban Studies PhD candidate, and has served as past president of Students in Transportation Engineering and Planning (STEP), PSU's transportation student group. He has also worked as a teaching assistant and research assistant at the Chinese University of Hong Kong. Nick's research specializes in transportation equity, focusing on mobility justice, transgender mobility, queer mobility, gender disparities, and marginalized communities. He earned his master's degree in community and regional planning from the University of New Orleans.

Connect with Nick on LinkedIn or view his PSU profile.

Follow Nick on Twitter @NickPuczkowskyj


Tell us about yourself?

Currently I'm a 5th year urban studies Phd candidate. Originally from Chicago, I also call Portland and Hong Kong home. Off campus, you can find me on the rugby pitch with the Portland Lumberjacks RFC or foraging Oregon’s forests for mushrooms.

What (or who...

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In 2020, the COVID-19 pandemic drastically impacted travel for in-person shopping, commute trips, global supply chains, and food business operations. E-grocery pickup and delivery services saw unprecedented expansions in response. The adoption and use of these e-grocery services have implications for equity and mobility. A PSU masters thesis offers insights: "Adoption and Use of E-Grocery Shopping in the Context of the COVID-19 Pandemic: Implications for Transport Systems and Beyond" by Gabriella Abou-Zeid, a 2021 graduate of Portland State University with a masters in civil engineering.

"While the future adoption and use of e-grocery services is uncertain as the COVID-19 pandemic evolves, our analysis revealed a clear impact of the pandemic on e-grocery shopping behaviors, which has impacts for transportation network demand, safety, and equity," Abou-Zeid said.

Enhancing our understanding of the drivers of (and barriers to) online grocery shopping and its potential "stickiness"—or the extent to which e-grocery use will continue at the same or higher frequencies after the pandemic—is a prerequisite for unpacking current and future consequences of this ecommerce sector on people...

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Incorporating transportation into the land development process is a big undertaking, with many important angles to be considered. Researchers are translating NITC research on this theme into a popular, easy-to-understand graphic format: comics. Led by an interdisciplinary team at Portland State University and the University of Arizona, they're illustrating transportation considerations in the land development process as a comic to reach a broader audience on this critical topic. 

Related: Read about the NITC Research Roadmap on Transportation and Land Use.

Still in development (the images here are early working drafts, illustrated by PSU student Joaquin Golez and Portland, OR illustrator Ryan Alexander-Tanner), the comics are based on research findings from several projects funded by the National Institute for Transportation and Communities (NITC). The project team is working with readers at neighborhood associations and nonprofits to test this unique approach in sharing research findings. We interviewed three of the project team members Kelly Clifton of PSU, Ryan Alexander-Tanner and Susan Kirtley of PSU to hear how it's going.

Can you share more about...

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Would monetary incentives encourage more people to buy e-bikes? 

Portland State University (PSU) researchers are examining how purchase incentive programs can expand the current e-bike market, and the latest product to come out of this research is a white paper released earlier this month: “Using E-Bike Purchase Incentive Programs to Expand the Market – North American Trends and Recommended Practices (PDF)

The paper offers methods of identifying the most effective program structure for the incentive provider's priorities, and helpful information on how to administer and track the program. 

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How could a free transportation class for people living in the Salt Lake City region strengthen community conversations and advocacy around local priorities in transportation policy? Researchers at Portland State University (PSU) and University of Utah (UU) explored that question by bringing a well-known learning model from Portland, Oregon to SLC.

For over 25 years, the Portland Bureau of Transportation has partnered with PSU to offer the Portland Traffic and Transportation Course – a free 10-week course designed to provide local community members the skills and knowledge to participate in transportation decisions affecting their neighborhoods. This model has proven to be a success story in public agency-university partnership in community education. Building upon a 2015 project that documented the Portland course and developed a curriculum handbook, the National Institute for Transportation and Communities (NITC) has provided more funding for a pilot community transportation class–the Wasatch Transportation Academy– in Salt Lake, City Utah. Their first class was held on January 24, 2022 (view class recordings here) and ran through...

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