Portland State University

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Nicholas Stoll, Graduate Research Assistant, Portland State University

Topic: Utilizing High Resolution Bus GPS Data to Visualize and Identify Congestion Hot-spots in Urban Arterials

The research uses high resolution bus data to examine sources of delay on urban arterials. A set of tools were created to help visualize trends in bus behavior and movement, which allowed for larger traffic trends to be visualized along urban corridors and urban streets. By using buses as probes and examining aggregated bus behavior, contoured speed plots were used to understand the behavior of roadways outside the zone of influence of bus stops. These speed plots can be utilized to discover trends and travel patterns with only a few days’ worth of data. Congestion and speed variation can be viewed by time of day and plots can help indicate delays caused by intersections, crosswalks, or bus stops.

This type of information is important to transit authorities looking to improve bus running times and reliability. Congested areas can be detected and ranked. Speed plots...

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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Andy Kading, Graduate Student Researcher, Portland State University

Topic: Managing User Delay with a Focus on Pedestrian Operations

Across the U.S, walking trips are increasing. However, pedestrians still face significantly higher delays than motor vehicles at signalized intersections due to traditional signal timing practices of prioritizing vehicular movements. This study explores pedestrian delay reduction methods via development of a pedestrian priority algorithm that selects an operational plan favorable to pedestrian service, provided a user defined volume threshold has been met for the major street. This algorithm, along with several operational scenarios, were analyzed with VISSIM using Software-In-The-Loop (SITL) simulation to determine the impact these strategies have on user delays. One of the operational scenarios examined was that of actuating a portion of the coordinated phase, or actuated-coordinated operation. Following a discussion on platoon dispersion and the application of it in the design of actuated-coordinated signal...

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The video begins at 2:53.

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-level. This residential choice model was applied in the...