Post date: Wed, 01/07/2015 - 10:20am
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Content Type: News Item

Transportation Cost Index: A Comprehensive Performance Measure for Transportation and Land Use Systems and its Application in OR, FL, and UT” is a Portland State University research project that will be presented at the 2015 annual meeting of the Transportation Research Board.

Portland State University researchers Liming Wang and Jenny Liu are developing a comprehensive performance measure that enables planners and the public to evaluate the performance of transportation and land use systems over time and across geographic areas.

Transportation engineers have a long history of using performance measures such as the Highway Performance Monitoring...

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Post date: Thu, 12/11/2014 - 2:43pm
Event Date:
Feb 20, 2015
Content Type: Events

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ORcycle is a new smartphone application (for both Android and iOS) developed by Transportation, Technology, and People (TTP) lab researchers at Portland State University as part of an Oregon Department of Transportation (ODOT) research project. ORcycle collects user, route, infrastructure, crash, and safety data. ORcycle was successfully launched in early November 2014 and presents many improvements over existing or similar apps. Initial data findings and insights will be presented. Lessons learned as well as opportunities and challenges associated with smartphone data collection methods will be discussed. More information about the app can be found here: http://www.pdx.edu/transportation-lab/orcycle

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Post date: Wed, 12/03/2014 - 3:06pm
Event Date:
Oct 10, 2008
Content Type: Events

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A System-Wide Adaptive Ramp Metering (SWARM) system is being implemented in the Portland metropolitan area and should be operational on all corridors by April 2006. This study entails a before and after evaluation of the operational benefits of the new SWARM system using the existing data, surveillance and communications infrastructure. In particular, the study will quantify system-wide benefits in terms of savings in delay, emissions and fuel consumption and safety improvements on and off the freeway due to the implementation of the ramp metering system. This will aid in the optimal deployment of current SWARM system and will be transferable to other regions as their systems come on line in the future.

Post date: Wed, 12/03/2014 - 3:03pm
Event Date:
Oct 17, 2008
Content Type: Events

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The video begins at 1:25.

Post date: Wed, 12/03/2014 - 2:00pm
Event Date:
Jan 23, 2009
Content Type: Events

The proliferation of information technology in the transportation field has opened up opportunities for communication and analysis of the performance of transportation facilities. The Highway Capacity Manual relies on rules of thumb and small data samples to generate levels of service to assess performance, but modern detection technology gives us the opportunity to better capture the dynamism of these systems and examine their performance from many perspectives. Travelers, operations staff, and researchers can benefit from measurements that provide information such as travel time, effectiveness of signal coordination, and traffic density. In particular, inductive loop detectors show promise as a tool to collect the data necessary to generate such information. But while their use for this purpose on restricted‐access facilities is well understood, a great many challenges remain in using loop detectors to measure the performance of surface streets.

This thesis proposes 6 methods for estimating arterial travel time. Estimates are compared to simulated data visually, with input/output diagrams; and statistically, with travel times. Methods for estimating travel time are applied to aggregated data and to varying detector densities and evaluated as above. Conclusions are drawn about which method provides the best estimates, what levels of data aggregation can still provide useful information, and what the effects of detector density are on the quality of estimates....

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Post date: Tue, 11/25/2014 - 3:45pm
Event Date:
May 01, 2009
Content Type: Events

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Abstract: The concept of accessibility has long been theorized as a principal determinant of household residential choice behavior. Research on this influence is extensive but the empirical results have been mixed, with some research suggesting that accessibility is becoming a relatively insignificant influence on housing choices. Further, the measurement of accessibility must contend with complications arising from the increasing prevalence of trip-chains, non-work activities, and multi-worker households, as well as reconcile person-specific travel needs with household residential decisions. This paper contributes to the literature by addressing the gap framed by these issues and presents a novel residential choice model with three main elements of innovation. First, it operationalized a time-space prism (TSP) accessibility measure, which the authors believe to be the first application of its kind in a residential choice model. Second, it represented the choice sets in a building-level framework, the lowest level of spatial disaggregation available for modeling residential choices. Third, it explicitly examined the influence of non-work accessibility at both the local- and person-...

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Post date: Tue, 11/25/2014 - 1:21pm
Event Date:
Apr 23, 2010
Content Type: Events

The video begins at 2:21.

Abstract:

Adaptive signal systems have been deployed in a number of locations across the country though their high maintenance requirements and additional cost have limited their widespread use. Adaptive systems adjust phases and timings at a network of signals in real time to improve traffic operations, particularly along congested corridors.

Rhythm Engineering has developed a new video detection-based system that vastly reduces the cost of deployment and maintenance. However, no existing microsimulation software could model the system due to its innovative methodology.

The methodology involves doing away completely with concept of cycle lengths, splits, and offsets, key parameters use in traffic signal analysis today. HDR and Rhythm Engineering joined together to develop a tool to act as middleware between the adaptive system and VISSIM that would emulate video detection, send the "video" to the adaptive controller, run the adaptive controller algorithm, and transmit detector calls back to VISSIM for inclusion in the model.

This presentation will discuss the lessons learned in the development of the emulation of video detection within VISSIM as well as showing the improvements in traffic operations provided by the system. It will also discuss the implications of the system's architecture and the impact it will have on not only adaptive signal systems...

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Post date: Tue, 11/25/2014 - 1:07pm
Event Date:
May 28, 2010
Content Type: Events

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Abstract: Existing regional travel forecasting systems are not typically set up to forecast usage of bicycle infrastructure and are insensitive to bicyclists' route preferences in general. We collected revealed preference, GPS data on 162 bicyclists over the course of several days and coded the resulting trips to a highly detailed bicycle network model. We then use these data to estimate bicyclist route choice models. As part of this research, we developed a sophisticated choice set generation algorithm based on multiple permutations of labeled path attributes, which seems to out-perform comparable implementations of other route choice set generation algorithms. The model was formulated as a Path-Size Logit model to account for overlapping route alternatives. The estimation results show compelling intuitive elasticities for route choice attributes, including the effects of distance and delay; avoiding high-volumes of vehicular traffic, stops and turns, and elevation gain; and preferences for certain bike infrastructure types, particularly at bridge crossings and off-street paths. Estimation results also support segmentation by commute versus non-commute trip types, but are less clear when it comes to gender. The final model will be implemented as part of the regional travel forecasting system for Portland, Oregon, U.S.A.
Post date: Tue, 11/25/2014 - 1:04pm
Event Date:
Jun 04, 2010
Content Type: Events

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Abstract: We propose to decompose residential self-selection by understanding its formation process. We take a life course perspective and postulate that locations experienced early in life have a lasting effect on our locational preferences in life. In other words, what was experienced spatially is a key factor contributing to our residential self-selection and our preferences in residential locations are formed long before our own self-selection begins.  We further hypothesize that prior locational influence interacts with period effect such that the same location experienced in different periods may have distinct effects.  Using an empirically collected dataset in the New York Metropolitan Region, we estimated a series of models to test these hypotheses. The results demonstrate that prior locational influence precedes residential self-selection. Furthermore, we show a variety-seeking behavioral pattern resulted from locations experienced during adolescence.

Post date: Mon, 11/24/2014 - 4:45pm
Event Date:
Oct 29, 2010
Content Type: Events

Video begins at 3:33.

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