Portland State University

Sirisha Kothuri, an OTREC scholar for the past two years and a current Ph.D. candidate at Portland State University, has been awarded one of NITC'S 2013 dissertation fellowships.

The $15,000 fellowship -- funded through an ISS (Institute for Sustainable Solutions) grant -- along with an $800 OTREC/NITC scholarship for the 2012-2013 academic year, will assist Kothuri with her research into pedestrian signal timing.

Sirisha was born and raised in Hyderabad, India, and still misses the heat — or at least, the warmth; she has yet to become completely acclimated to Portland, Ore weather. In Hyderabad she obtained a bachelor's degree in Civil Engineering from Osmania University in 1999. She moved to Baton Rouge, Louisiana in 1999 to get a Master’s degree in Civil Engineering at Louisiana State University.

A visit to Illinois for her brother's graduation opened her eyes to the automobile-centric cities that make up much of the United States. She was surprised at some of the infrastructure in the Midwest, which decidedly favors cars over pedestrian and other means of active transport.

Walking plays a significant...

Each year, Portland State University’s MURP, or Master’s of Urban and Regional Planning, program hosts a public presentation to showcase the work of its graduating master’s students. Students who graduate with a Master’s in Urban and Regional Planning spend the last two terms of their program collaborating on workshop projects, completing planning tasks for local clients or business organizations.

This year’s presentations took place on Wednesday, attended by a crowd of about a hundred PSU students, professors, MURP clients and community members. Six groups presented their projects. Some of the projects were transportation-focused, especially one titled "Lombard Re-Imagined."

Swift Planning Group, composed of members Kathryn Doherty-Chapman, Zef Wagner, Brian Hurley, Jake Warr, Rebecca Hamilton, and Jodi Jacobson-Swartfager, developed a plan to improve Lombard Street, a key transportation corridor in North Portland.

The challenge facing the group had to do with the many roles that Lombard street plays. The street is both an arterial throughway and a state highway. It is an overdimensional freight route, for trucks that are too big to go anywhere else in North Portland, and it has also been designated as a main street in Metro’s 2040 Growth Concept. The various...

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...

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...