When planning their daily commute, most drivers account for the traffic they know is unavoidable: at peak times of day, like morning and afternoon rush hour, they probably allow extra time to get where they’re going.

The delays that are harder to accept are the unexpected ones, when accidents, road work, or a traffic bottleneck turn a thirty minute trip into an hour.

This unpredictable postponement leads to natural frustration on the part of drivers, as it may cause them to be late to work or late picking up children from school. A reliable road network is one in which this is a rare occurrence.

A project led by Portland State University’s Miguel Figliozzi explored the value of this travel-time reliability using a study of commuters’ route choice behavior, taking a look at the trade-offs between reliability, traffic congestion, and air pollution.

The details for the combined project can be found here.

In the first phase of the research, co-investigators David Levinson and Kathleen Harder of the University of Minnesota sought to measure the route choices drivers made in a real-world setting. Instead of just having people fill out a survey about whether they would choose to take major roads or the freeway to work, this study ambitiously...

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Graduate student researcher Alex Bigazzi, of Portland State University, will present his work in Vietnam next week.

The Asia-Pacific Economic Cooperation (APEC) is hosting a transportation workshop in Ho Chi Minh city. The opportunity for Bigazzi to attend is the result of a spontaneous connection he made recently at a conference in Annapolis, Maryland, where he was giving a paper on truck-specific traffic management.

Large trucks contribute a large share of emissions, especially when traveling at a slow crawl through heavy traffic. Bigazzi’s work explores ways to mitigate the effects of this traffic congestion on air quality.

Bigazzi presented two papers at the 54th Annual Transportation Research Forum, which took place March 21-23 in Annapolis. One of them, “The Emissions Benefits of Truck-Only Lane Management,” offers a better understanding of the impacts of congestion on heavy-duty vehicles.

After a question-and-answer exchange, he was invited to present the same research in Vietnam’s largest city.

APEC’s 37th Transportation Working Group Meeting will take place April 8th through the 12th, 2013, at a Sheridan...

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While the national parks system may have some of the most natural areas in America, there’s nothing natural about how most Americans travel through them: by car.

Todd Johnson, an OTREC graduate research assistant, is hoping to change that for at least one state park. The Eno Transportation Foundation recently chose Johnson for a year-long assignment to find ways to reduce traffic congestion at Arches National Park near Moab, UT.  Every year, Eno puts out five assignments throughout the country to improve transportation at national parks and monuments.

Johnson, a Master of Science student in civil and environmental engineering at Portland State University, previously worked as a transportation interpreter at Rock Mountain National Park, encouraging people to take a shuttle service rather than driving.  He has a similar goal for his stint at Arches.

“We want to get people out of their cars,” Johnson said. “Right now when the parking lots fill up, people park on the side of the road, creating a safety hazard and diminishing the beauty of the park. I will help with implementing solutions to deal with congestion using (Intelligent Transportation Systems) and social media.”

Johnson, an avid cyclist, will also be looking at encouraging alternative forms of transportation through Arches. The park is looking to construct more hiking and biking trails to prevent visitors from driving from one attraction to another, Johnson said. Currently, the park’s roads...

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Every day, trucks travel in, out and through Portland delivering the goods that make the city and region’s economy thrive. But urban freight traffic in the Portland metro area has become increasingly congested and unreliable, leading to longer travel times, fewer goods being distributed and more greenhouse gases being emitted. OTREC researchers have worked with commercial vehicle GPS data and freeway traffic sensor data to understand the impact of urban congestion on commercial vehicle fleets and what can be done to reduce congestion.

In “Algorithms to Quantify the Impacts of Congestion on Time-Dependent Real-World Urban Freight Distribution Networks” (Read Paper Here) and “The Impacts of Congestion on Time-definitive Urban Freight Distribution Networks CO2 Emission Levels” (Read Paper Here), OTREC researcher Miguel Figliozzi and his team attempted to quantify and measure the impacts of congestion on freight from a business, as well as environmental perspective. The project team combined time-dependent algorithms, real-world traffic data, and open source software Google Maps to...

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View Nicholas Stoll's presentation slides

View Nicholas Kobel's presentation slides

Nicholas Stoll, Graduate Research Assistant, Portland State University

Topic: Utilizing High Resolution Bus GPS Data to Visualize and Identify Congestion Hot-spots in Urban Arterials

The research uses high resolution bus data to examine sources of delay on urban arterials. A set of tools were created to help visualize trends in bus behavior and movement, which allowed for larger traffic trends to be visualized along urban corridors and urban streets. By using buses as probes and examining aggregated bus behavior, contoured speed plots were used to understand the behavior of roadways outside the zone of influence of bus stops. These speed plots can be utilized to discover trends and travel patterns with only a few days’ worth of data. Congestion and speed variation can be viewed by time of day and plots can help indicate delays caused by intersections, crosswalks, or bus stops.

This type of information is important to transit authorities looking to improve bus running times and reliability. Congested areas can be detected and ranked. Speed plots...

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