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....Read more
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-...Read more
The video begins at 2:21.
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...Read more
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.
Video begins at 3:33.
The video begins at 2:26.
Abstract: This report offers a new view of urban transportation performance. It explores the key role that land use and variations in travel distances play in determining how long Americans spend in peak hour travel. It shows how the key tool contained in the Urban Mobility Report – the Travel Time Index – actually penalizes cities that have shorter travel distances and conceals the additional burden caused by longer trips in sprawling metropolitan areas. Finally, it critically examines the reliability and usefulness of the methodology used in the Urban Mobility Report, finding it does not accurately estimate travel speeds, it exaggerates travel delays, and it overestimates the fuel consumption associated with urban travel. How we measure transportation systems matters, and the nation needs a better set of measures than it has today.
The video begins at 2:51.
Adam Moore: Bus Stop Air Quality: An Empirical Analysis of Exposure to Particulate Matter at Bus Stop Shelters
Congested traffic corridors in dense urban areas are key contributors to the degradation of urban air quality. While waiting at bus stops, transit patrons may be exposed to greater amounts of vehicle-based pollution, including particulate matter, due to their proximity to the roadway. Current guidelines for the location and design of bus stops do not take into account air quality or exposure considerations. This study compares the exposure of transit riders waiting at three-sided bus stop shelters that either: 1) face the roadway traffic or 2) face away from the roadway traffic. Shelters were instrumented with air quality monitoring equipment, sonic anemometers, and vehicle counters. Data were collected for two days at three shelters during both the morning and afternoon peak periods. Bus shelter orientation is found to significantly affect concentration of four sizes of particulate matter: ultrafine particles, PM1, PM2.5, and PM10. Shelters with an opening oriented towards the roadway were consistently observed to have higher concentrations inside the shelter than outside the shelter. In contrast, shelters oriented away from the roadway were observed to have lower concentrations inside the shelter than outside the shelter. The differences in particulate matter...Read more
The video begins at 2:00.
Abstract: Urban arterials often represent complex venues of transportation operations, co-mingling non-motorized users with transit services and a wide variety of land uses and traffic patterns. This presentation presents results related to the evaluation of a new Adaptive Traffic Control System (SCATS) on Powell Boulevard in southeast Portland. The presentation will discuss challenges and opportunities associated with the evaluation of new technologies and the development of comprehensive urban arterial performance measures.
Speaker Bio: Miguel Figliozzi is an Associate Professor of Civil and Environmental Engineering at Portland State University. His diverse research interests include transit and traffic operations, bicycle and pedestrian modes, emissions and air quality modeling, and freight and logistics. He holds a MS from the University of Texas at Austin and a PhD from the University of Maryland College Park. Figliozzi is a member of the Transportation Research Board Network Modeling Committee, Freight and Logistics, and Intermodal Terminal Design Committees. Papers, reports, and more detailed information available at Figliozzi's webpage: http://web.cecs.pdx.edu/~...Read more