Flashing-yellow-arrow traffic signals offer convenience for drivers by permitting them to turn left after yielding to oncoming traffic. This convenience, OTREC research has found, can come at the expense of safety, especially where the traffic mix includes pedestrians.
OTREC researchers David Hurwitz of Oregon State University and Christopher Monsere of Portland State University examined how driver behaviors affect pedestrian safety at flashing yellow arrows. Their findings show that drivers at these intersections often don’t even look for pedestrians.
This research will be the focus of OTREC’s first live interview-style Webinar May 7. Host Steph Routh of Oregon Walks will interview the researcher-practitioner team, explore real-world applications and take audience questions. The Webinar is free. Details are at this link:
Flashing yellow arrows have been replacing other left-turn signals, such as solid green or flashing yellow or red circles, to indicate that drivers may turn after yielding to oncoming traffic. These turns are considered “permissive.” Turns where no conflicting traffic is present, such as those indicated with a green arrow, are “protected” turns. The flashing yellow arrow’s inclusion in the 2009 Manual on Uniform Traffic Control Devices sped up the signal’s adoption to...
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Bicycle commuters represent a significant chunk of business consumers in Portland, Ore., one of America's most bike-friendly cities. OTREC research in the past year has provided data on how cyclists and other mode users patronize local businesses.
During Hurricanes Ivan in 2004 and Katrina in 2005, at least 11 highway and railroad bridges along the U.S. Gulf Coast were damaged. When the water rose during the storms, wave forces slammed into the bridges’ supporting substructures, and when it rose high enough, the water’s buoyancy had enough power to lift off sections of a bridge’s superstructure and lay them aside like giant Legos.
To build bridges that can withstand the force of hurricane waves, engineers must be able to estimate the effects those waves will have on bridge structures. An OTREC project led by Oregon State University professor Daniel Cox examined the effects of wave loading on highway bridge superstructures.
Cox and co-investigator Solomon C. Yim, also of Oregon State University, conducted experiments in the Large Wave Flume at the O.H. Hinsdale Wave Research Laboratory at Oregon State University. They used a 1:5 scale, reinforced concrete model of a section of the Interstate 10 Bridge over Escambia Bay, Fla, which failed during Hurricane Ivan.
To see more details about the project, “Hurricane Wave Forces on Highway Bridge Superstructure,” click here, or download the final report.
The...
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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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David Timm, P.E., the Brasfield & Gorrie Professor of Civil Engineering at Auburn University, traveled to Oregon in mid-March as part of the NITC Visiting Scholar program.
Timm is recognized nationally and internationally as a leading expert in the field of perpetual pavement, a sustainable approach to pavement design. He is also the author of a perpetual pavement design software, PerRoad. Engineers in this field have developed a pavement system that has the potential to last for up to 50 years, with only minor periodic surface repairs.
The visit, arranged by Oregon Tech’s NITC Executive Committee member Roger Lindgren, started with a March 13 PerRoad workshop in Salem. The workshop was attended by designers from industry and from the Oregon Department of Transportation (ODOT).
On March 14, Timm led another PerRoad workshop on the campus of Oregon Institute of Technology in Klamath Falls. Following the workshop was a presentation, focusing on perpetual pavement design and the advancements being made at Auburn’s National Center for Asphalt Technology (NCAT).
The Klamath Falls workshop was attended by 14 engineers and engineering students, with 53 people attending the presentation afterward.
Oregon Tech students boosted their knowledge of sustainable pavement on a conference field trip and brought what they learned back to fellow engineering students on their Klamath Falls campus. Students Jared Jones, Zachary Hudspeth, Michael Eagle and Adam Kershaw attended the Oregon Asphalt Conference in Eugene March 5, sponsored by an OTREC student-support grant. Hudspeth, the ITE Student Chapter president, led the group.
The conference was organized by the Asphalt Pavement Association of Oregon (http://www.apao.org/2013ConfProgram2.htm).
The Oregon Tech students were especially interested in hearing about advances in warm-mix asphalt and RAP (reclaimed asphalt pavement). These two asphalt pavement technologies greatly reduce greenhouse gas emissions compared to traditional asphalt paving.
After returning to campus, the students shared their experiences with students enrolled in Oregon Tech’s Civil Engineering 573 Transportation and Land Development class.
A new OTREC research project, in partnership with the Oregon Department of Transportation, will evaluate the effectiveness of a program to promote "ecodriving," or fuel-efficient driving.
The ODOT program seeks to help the state reduce greenhouse gas emissions by giving commercial drivers training in ecodriving practices.
Led by Portland State University’s Donald Truxillo and John MacArthur, the project was one of the OTREC “Small Starts” grant winners announced earlier this month. The researchers are working with ODOT program manager Stephanie Millar.
ODOT’s effort, rather than concentrating on individual drivers, focuses on entities with a fleet of vehicles at their disposal. Entities — such as the city of Portland, or private, commercial companies — who maintain a fleet of cars and/or trucks will be given materials to educate their employees on ecodriving. It is part of a larger effort on Oregon’s part to reduce harmful emissions and help stop global climate change.
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The Beaverton-Hillsdale Highway, pegged as one of Portland’s high-crash corridors, already attracted the attention of city officials worried about safety. They got more help from Portland State University students during the recently completed term.
Students from civil engineering professor Christopher Monsere’s transportation safety analysis course formed six groups, each studying a piece of the corridor. They presented their findings and recommendations during the course’s open house March 19. The presentation drew officials from local agencies interested in improving corridor safety, including the city of Portland, the TriMet transit agency and the Metro regional government.
The student work dovetails with the city’s own examination of the highway corridor, completed in February. In some cases, as with the Shattuck Road intersection, the students came to many of the same conclusions as city officials, said Wendy Cawley, traffic safety engineer with the Portland Bureau of Transportation. Both found that narrowing the crossing distance could make that intersection safer for pedestrians.
One group looked at the Hillsdale area, recommending a “road diet” approach and other livability-minded changes. While it’s “probably a little more than the city will be able to recommend and handle,” Cawley said, the work has inspired...
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OTREC extends a warm welcome to Research Associate Krista Nordback, Ph.D., P.E., the newest member of the team. She just moved to Portland, Oregon after finishing up her Ph.D. in Denver, Colorado, to continue working on her favorite research focus: urban bicycle safety.
Nordback has been riding bikes since before she was old enough to remember. Together with her husband, Kurt, she continues to enjoy it as a form of both recreation and transportation. When the pair moved to Portland in February of this year, one of their first actions was to bike the Springwater Corridor, the Portland metro area’s 21-mile bike trail, all the way from Portland to Boring on their semi-recumbent tandem.
As a bicycle commuter, safety is one of Nordback’s top priorities, and it’s also the primary goal of her civil engineering research. In her PhD thesis, “Estimating Annual Average Daily Bicyclists and Analyzing Cyclist Safety at Urban Intersections,” she came up with methods for determining the average number of cyclists passing through a given intersection on a daily basis. In order to increase bicycle safety measures in urban areas, one of the first steps is simple yet essential: count the bikes. Having an understanding of the numbers of bicycles that traffic through an area is the starting point for coming up...
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