Network Congestion Effect of E-Hailing Transportation Services

E-hailing plays a key role in emerging transportation services such as ridesourcing, ridesharing and taxis, among others. This seminar will present a general economic model to analyze the congestion effect of e-hailing services in a transportation network. The model can help analyze customers’ choices of different modes, based on their value of time and the charging schemes of different services, as well as the overall impact of the services to network level congestion.https://pdxscholar.library.pdx.edu/trec_seminar/1119/thumbnail.jp

Measuring the Impacts of Social Media on Advancing Public Transit

This project is a collaboration between Portland State University (PSU) and the Center for Infrastructure Transportation & Environment (CITE) at Rensselaer Polytechnic Institute seeking to develop performance measures for assessing the impacts of social media on promoting public transit. Revolutionary changes have occurred in the communication landscape, and there has been a rapid diffusion of social media use as a means of communicating transit information to the public. Significant resources are being directed to the use of social media in communication, yet little effort exists that measures the impacts of these popular vehicles of communication. Rarely studied is the role of social media in achieving the overarching goals of advancing the mission of transit agencies through increasing recruitment and retention of transit riders; increasing resources and customer satisfaction; addressing system issues, performance efficiency and effectiveness; and improving employee productivity and morale. There is a need to measure the impacts of social media and account for the cost effectiveness of its wide use as a means of communication in public transit agencies. This research intends to extend understanding about whether investments in social media tools effectively achieve their intended purposes. The goal of this project is to identify social media-related measures for public transit agencies that can comprehensively capture the impacts of social media use on agency performance. This project will rely on a review of the research and practice literature to document findings in other fields on performance measures used to assess the impacts of social media. Best practices will be identified. A survey of a random sample of public transit agencies nationwide will target identifying performance measures currently used to document impacts. Gaps will be identified. Investigators will compare and contrast measures used in transit agencies and other fields and identify a list of performance measures that are most effective for transit agencies

A time-dependent freight tour synthesis model

This paper introduces a model of urban freight demand that seeks to estimate tour flows from secondary data sources e.g., traffic counts, to bypass the need for expensive surveys. The model discussed in this paper, referred as Freight Tour Synthesis (FTS), enhances current techniques by incorporating the time-dependent tour-based behavior of freight vehicles, and the decision maker’s (e.g., metropolitan planning agency planner) preferences for different sources of information. The model, based on entropy maximization theory, estimates the most likely set of tour flows, given a set of trip generation estimates, a set of traffic counts per time interval, and total freight transportation cost in the network. The type of inputs used allows the assessment of changes in infrastructure, policy and land use. The ability of the model to replicate actual values is assessed using the Denver Region (CO) as a case study

Link Travel Time Estimation in Double-Queue-Based Traffic Models

Double queue concept has gained its popularity in dynamic user equilibrium (DUE) modeling because it can properly model real traffic dynamics. While directly solving such double-queue-based DUE problems is extremely challenging, an approximation scheme called first-order approximation was proposed to simplify the link travel time estimation of DUE problems in a recent study without evaluating its properties and performance. This paper focuses on directly investigating the First-In-First-Out property and the performance of the first-order approximation in link travel time estimation by designing and modeling dynamic network loading (DNL) on single-line stretch networks. After model formulation, we analyze the First-In-First-Out (FIFO) property of the first-order approximation. Then a series of numerical experiments is conducted to demonstrate the FIFO property of the first-order approximation, and to compare its performance with those using the second-order approximation, a point queue model, and the cumulative inflow and exit flow curves. The numerical results show that the first-order approximation does not guarantee FIFO and also suggest that the second-order approximation is recommended especially when the link exit flow is increasing. The study provides guidance for further study on proposing new methods to better estimate link travel times

Towards fine-grained urban traffic knowledge extraction using mobile sensing

We introduce our vision for mining fine-grained urban traf-fic knowledge from mobile sensing, especially GPS location traces. Beyond characterizing human mobility patterns and measuring tra±c congestion, we show how mobile sensing can also reveal details such as intersection performance statis-tics that are useful for optimizing the timing of a tra±c sig-nal. Realizing such applications requires co-designing pri-vacy protection algorithms and novel tra±c modeling tech-niques so that the needs for privacy preserving and tra±c modeling can be simultaneously satisfied. We explore pri-vacy algorithms based on the virtual trip lines (VTL) con-cept to regulate where and when the mobile data should be collected. The tra±c modeling techniques feature an inte-gration of tra±c principles and learning/optimization tech-niques. The proposed methods are illustrated using two case studies for extracting tra±c knowledge for urban signalized intersection

DRONES FOR IMPROVING TRAFFIC SAFETY IN RITI COMMUNITIES IN WASHINGTON STATE

Transportation and traffic safety is a primary concern in Rural, Isolated, Tribal, or Indigenous (RITI) communities in Washington (WA) State. Parallel to this, while emerging technologies (e.g., connected/autonomous vehicles, drones) have been developed and tested in addressing traffic safety issues, they are often not widely shared in RITI communities for various reasons. Compared with other technological advances, drone technologies have been rapidly improved and can be flexibly applied to multiple fields, including engineering, agriculture and disaster managements. The goal of this study is to explore and synthesize the opportunities, challenges and scenarios that drone technologies can assist to resolve traffic safety related issues and concerns in RITI communities. Through the outreach activities with the outer Pacific Coast in WA state, it is found that the principal concern within these communities are disaster management and mitigation since they are facing the threat of coastal erosion, earthquake and tsunami. Thus, the emergency management and hazard mitigation becomes the major way to further explore drone applications in the selected communities. To achieve this, we reviewed the current state of the drone technologies, conducted surveys from National Guard and coastal communities in WA, including City of Westport, South Beach Region, Grays Harbor County, Shoalwater Bay Tribe, and Quinault Indian Nation, to better understand their current needs, challenges and issues. Ultimately, recommendations of drone applications under specific scenarios are provided based upon the integration of drone technologies with community safety needs.TABLE OF CONTENTS Disclaimer....................................................................................................................................................... i Technical Report Documentation Page ........................................................................................................ ii SI* (Modern Metric) Conversion Factors ..................................................................................................... iii List of Figures ................................................................................................................................................ v List of Tables ................................................................................................................................................ vi Executive Summary ....................................................................................................................................... 1 CHAPTER 1. Introduction .......................................................................................................................... 2 1.1. General Background ...................................................................................................................... 2 1.2. Problem Statement ....................................................................................................................... 3 CHAPTER 2. Literature review of drone technology and Application ....................................................... 5 2.1. State of the Art Drone Technologies............................................................................................. 5 2.2. Practice of drones in Washington State ........................................................................................ 6 CHAPTER 3. Outreach activities ................................................................................................................ 7 3.1. Community Engagement for Coastal Resilience Studio ................................................................ 8 3.1.1. Westport/South Beach Workshop – 11/2018 (27) ............................................................. 10 3.2. WA National Guard Workshop – 6/2019 .................................................................................... 11 CHAPTER 4. Online survey ...................................................................................................................... 14 CHAPTER 5. results and recommendationS ............................................................................................ 15 5.1. Outreach Activity Findings .......................................................................................................... 15 5.1.1. Transportation and Traffic Safety in Westport ................................................................... 15 5.1.2. Learning from WA National Guard Workshop .................................................................... 17 5.2. Online Survey Results.................................................................................................................. 18 5.3. Recommendation of drone applications .................................................................................... 18 CHAPTER 6. conclusion and future study ............................................................................................... 24 Reference .................................................................................................................................................... 25 Appendix A: UAV (Drones) technologies ...................................................................................................... 1 Appendix B: Workshop report for Westport Coastal Resilience................................................................... 1 Appendix C: Online Survey ............................................................................................................................ 1 Appendix D: Executive Summary of Westport Costal Resilience Report ...................................................... 1 Appendix E: Transportation Chapter of Westport Costal Resilience Report ................................................

Investigation of Drone Applications to Improve Traffic Safety in RITI Communities

Transportation and traffic safety is a primary concern among the Rural, Isolated, Tribal, or Indigenous (RITI) communities in the U.S. Although emerging technologies (e.g., connected and autonomous vehicles, drones) have been developed and tested in addressing traffic safety issues, they are often not widely shared in RITI communities for various reasons. This research aims to explore, understand, and synthesize the opportunities and challenges of applying drone technologies to alleviate or resolve traffic safety and emergency related issues within RITI communities. The project team first sent out online surveys to communities on the outer Pacific coast of Washington State and selected the City of Westport as the study area based on the feedback. A pilot study using drones for mapping and sensing in Westport was then conducted, followed by two community meetings to explore potential drone applications. With the three outreach activities, it was found that the current need in the communities was education on drones, including training for remote pilot certification (drone license) and drone operations. Findings of this research will help guide the project team to set up specific drone-related programs in the Westport area in future research