Apr 09, 2012

Although specialized equipment and vehicles make up a large portion of state transportation budgets, an OTREC research report found little consistency in how states decide to replace this equipment.

Researchers David Kim and David Porter of Oregon State University surveyed 25 state departments of transportation to determine how they made replacement decisions. Nearly all consider the age of the vehicle or piece of equipment, with many considering how much use it gets.

Around half use thresholds, such as number of miles or months in service, to identify candidates for replacement. Some consider the equipment’s repair cost or operating cost, while others rely on physical inspections. None explicitly considers greenhouse gas emissions or other environmental concerns in its replacement criteria.

Given the huge range of approaches, Kim and Porter wondered if modeling could lead to better decision-making. They ran various models against the simple approach of using equipment age as a threshold value.

As it turns out, the simple approach isn’t too bad. In fact, it does better than one complicated mathematical model and about the same as a second model.

Click here to learn more about the project and download the report.

That may...

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Apr 06, 2012

Transportation models keep growing more sophisticated. But complicated isn’t necessarily better, Rick Donnelly said during the inaugural seminar in OTREC’s spring 2012 transportation seminar series April 6.

“Better is contextual,” Donnelly said.

Donnelly, who leads the modeling and simulation practice at engineering consultancy Parsons Brinckerhoff, opened the spring seminar series with an introduction to models. Seven more free seminars follow in the series, produced in partnership with the Oregon Modeling Collaborative.

Donnelly detailed questions that model builders and users should ask and offered his thoughts on building more useful and informative models. Click here for a link to the archived presentation.

Although transportation models consider increasingly more information, simpler models can often get the job done with a smaller investment of time and money, Donnelly said. Sometimes the simplest approach actually produces the best results.

“’Better’ is only relevant in the context of what the model is going to be used for,” he said.

The modeling series continues Friday, April 13 with another seminar geared toward non-modelers. The seminar, by Ben Stabler, also of Parsons Brinckerhoff, builds on Donnelly’s opening installment.

Stabler will discuss two approaches to travel modeling and give examples of each approach....

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May 19, 2011

Even as complex visual representations of data become common, many people still don’t understand what land-use and transportation modelers do. In April, state and local planning directors met to address that and other issues they’ll increasingly face in the coming years. The Oregon Modeling Collaborative convened the Oregon Transportation Policy Forum for guidance in developing the tools agencies will need and to keep agencies talking about transportation issues.

Giving a complex topic such as global warming the video game treatment could make it easier to grasp, said Angus Duncan of the Oregon Global Warming Commission. “I have yearned for something that’s the greenhouse gas equivalent of a ‘Sim City,’ “ Duncan said at the forum. “Something simple enough that kids can play with it, but something you can use for communication.”

Developers have gotten much better at representing data, said Tom Schwetz, director of development services for Lane Transit District, but leaps in handheld devices such as iPhones have raised expectations still higher. Transportation models are getting more complex and, at the same time, people are demanding their information quicker and quicker.

Modelers struggle, Schwetz said, both because people don’t understand the complexity of the models and because modelers themselves don’t explain themselves clearly. The models then become easier to attack than to defend. “There is a credibility issue,” he said. “It’s too easy to...

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Nov 10, 2010

Good transportation decisions rely on good models. Yet, despite advances in transportation modeling, there had been no dedicated training ground for the next generation of modelers. That all changed with the launch of the Oregon Modeling Collaborative Nov. 12. The collaborative will serve as a living laboratory to put the research from some of America’s top modelers into practice across Oregon.

On Nov. 12, we welcomed Peter Appel, administrator of the federal Research and Innovative Technology Administration, to Portland to kick off the collaborative with researchers, practitioners and policymakers from across the Northwest. Appel, confirmed by the U.S. Senate as administrator in 2009, has worked on U.S. Department of Transportation initiatives aimed at getting researchers and professionals to address safety, efficiency and environmental sustainability across all forms of transportation.

Groundbreaking research at the Oregon Transportation Research and Education Consortium has already produced models to account for bicycle trips and greenhouse gas emissions and to predict earthquake risk to highway bridges. However, models don’t do any good if agencies can’t afford the staff time and resources to use them. The Oregon Modeling Collaborative helps fill this gap by educating the next generation of...

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