National Institute for Transportation and Communities

An OTREC research project recently took a look at gusset plate connections, the riveted plates of sheet metal that hold steel truss bridges together.

These connective plates have come to the attention of the Federal Highway Administration (FHWA), because in 2007 the collapse of the Interstate-35W Bridge in Minneapolis was the result of a failed gusset plate.

After the collapse, which killed 13 people and injured 145, the FHWA issued a set of guidelines for load rating — or determining the weight-bearing capacity — of gusset plates.

Historically, only bridge truss members were considered for load rating during safety inspections. Gusset plates were thought to be reliable based on conservative assumptions employed during their design.

For more details, visit the project page.

Roughly 20,000 steel bridges in the United States are classified as non-load-path-redundant, or fracture critical, bridges. This means that the failure of a single truss member or connection could lead to collapse.

The problem, says the project's lead investigator Christopher Higgins, happens when a plate goes out of plane. It’s supposed to be perfectly flat, but with too much load put on it, it can develop a bifurcation and go from stable to unstable.

“It’s...

Six graduate students from the Master of Urban and Regional Planning program at Portland State University have been awarded a national prize by the American Planning Association.

The research team, working under the name Celilo Planning Studio, won the 2013 APA student award for Application of the Planning Process.

Team members Danielle Fuchs, Michael Ahillen, Ellen Dorsey, Chloe Ritter, Sara Morrissey and Sarah Bronstein were honored for excellence in the way they carried out their project plan.

Ritter, Morrissey and Bronstein accepted the award on behalf of the group at the APA national conference this month in Chicago.

“We were very excited to attend APA and receive the award,” said Morrissey, the team’s communications director. “The conference is great to learn about what other cities are working on and get a feel of what’s going on.”

Morrissey and other members of the planning team have OTREC connections. She and Chloe Ritter worked with PSU professor Kelly Clifton on a consumer spending project, with a focus on cyclists and pedestrians. Sarah Bronstein has also worked on...

The quality of OTREC research has recently been recognized on a national level.

Selected data from the Portland Oregon Regional Transportation Archive Listing (PORTAL) will be part of a new national data sharing platform.

The US Department of Transportation has released the first version of this platform, called the Research Data Exchange, which collects and publishes archived and real-time transportation data from multiple sources.

In the language of their home page, the Research Data Exchange (called the RDE for short) was primarily developed to “support the development, testing, and demonstration of multi-modal transportation mobility applications being pursued under the USDOT ITS Dynamic Mobility Applications (DMA) Program and other connected vehicle research activities.”

In other words, USDOT created this database so they could use it. But – in the spirit of collaboration common to those with an interest in collecting and managing vast amounts of information – they’re sharing it.

The RDE is free and open to the public. Registered users...

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-arrow Webinar

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...