Transportation Commons^™

A Simulator-Based Analysis Of Engineering Treatments For Right-Hook Bicycle Crashes At Signalized Intersections, Jennifer Warner, David S. Hurwitz, Christopher M. Monsere, Kayla Fleskes

Civil and Environmental Engineering Faculty Publications and Presentations

A right-hook crash is a crash between a right-turning motor vehicle and an adjacent through-moving bicycle. At signalized intersections, these crashes can occur during any portion of the green interval when conflicting bicycles and vehicles are moving concurrently. The objective of this research was to evaluate the effectiveness of four types of engineering countermeasures – regulatory signage, intersection pavement marking, smaller curb radius, and protected intersection design – at modifying driver behaviors that are known contributing factors in these crashes. This research focused on right-hook crashes that occur during the latter stage of the circular green indication at signalized intersections …

Feasibility Study Of A Campus-Based Bikesharing Program At Unlv, Hualiang Teng, Boniphace Kutela, Eneliko Mulokozi, Bingyi Hu, Yang Jiao, Haiqing Li

Mineta Transportation Institute

Bikesharing systems have been deployed worldwide as a transportation demand management strategy to encourage active modes and reduce single-occupant vehicle travel. These systems have been deployed at universities, both as part of a city program or as a stand-alone system, to serve for trips to work, as well as trips on campus. The Regional Transportation Commission of Southern Nevada (RTCSNV) has built a public bikesharing system in downtown Las Vegas, approximately five miles from the University of Nevada, Las Vegas (UNLV). This study analyzes the feasibility of a campus-based bikesharing program at UNLV. Through a review of the literature, survey …

Designing Road Diet Evaluations: Lessons Learned From San Jose’S Lincoln Avenue Road Diet, Hilary Nixon, Asha Weinstein Agrawal, Cameron Simons

Mineta Transportation Institute

This report analyzes traffic impacts from the 2015 implementation of a pilot “road diet” on Lincoln Avenue, in the City of San Jose, California, comparing data on traffic volumes and speeds from before and after the road diet was implemented. The analysis looks at impacts on both the road diet location itself and on surrounding streets likely to have been impacted by traffic diverted off the road diet segment. The results within the road diet zone were as expected, with falling volumes and numbers of speeders. The all-day data aggregated by street type (e.g., neighborhood streets, major streets) showed limited …

Incentivizing The Use Of Bike Trailers For Dynamic Repositioning In Bike Sharing Systems, Supriyo Ghosh, Pradeep Varakantham

Research Collection School Of Computing and Information Systems

Bike Sharing System (BSS) is a green mode of transportation that is employed extensively for short distance travels in major cities of the world. Unfortunately, the users behaviour driven by their personal needs can often result in empty or full base stations, thereby resulting in loss of customer demand. To counter this loss in customer demand, BSS operators typically utilize a fleet of carrier vehicles for repositioning the bikes between stations. However, this fuel burning mode of repositioning incurs a significant amount of routing, labor cost and further increases carbon emissions. Therefore, we propose a potentially self-sustaining and environment friendly …

Algorithms For Constructing Vehicle Trajectories In Urban Networks Using Inertial Sensors Data From Mobile Devices, Umana Ahmed

Computational Modeling & Simulation Engineering Theses & Dissertations

Vehicle trajectories are an important source of information for estimating traffic flow characteristics. Lately, several studies have focused on identifying a vehicle’s trajectory in traffic network using data from mobile devices. However, these studies predominantly employed GPS coordinate information for tracking a vehicle’s speed and position in the transportation network. Considering the known limitations of GPS, such as, connectivity issues at urban canyons and underpasses, low precision of localization, high power consumption of device while GPS is in use, this research focuses on developing alternate methods for identifying a vehicle’s trajectory at an intersection and at a urban grid network …

A Nash Equilibrium Formulation Of A Tradable Credits Scheme For Incentivizing Transport Choices: From Next-Generation Public Transport Mode Choice To Hot Lanes, Salem Lahlou, Laura Wynter

Research Collection School Of Computing and Information Systems

We consider a tradable credits scheme for binary transport games where one option is faster (or more comfortable) than the other, but its quality of service suffers when usage is high. Applications can be found in mode choice (public transit versus road transport), premium (i.e., express bus) versus ordinary public transit, and fast (e.g., high-occupancy toll, or HOT) versus regular lanes on expressways. We are motivated in particular by the choice between public transport and use of the road network as a privilege to be discouraged. In a future where GPS-based time-distance-place road charging exists, such next-generation transport management strategies …

Assessing And Mitigating The Environmental Impacts Of Shipping In The Arctic, Lilitha Pongolini, Jonas Pålsson, Jennie Folkunger, Jennie Larsson, Anne Bouyssou, Lawrence Hildebrand, Neil Bellefontaine

Assessing and mitigating the environmental impacts of shipping in the Arctic

Report by World Maritime University for the Total Foundation project "Assessing and mitigating the environmental impacts of shipping in the Arctic - Focus on the introduction of invasive species and pathogens".

China's Motorization Wave And The Place Of Emerging Technologies, Christopher Cherry

PSU Transportation Seminars

E-bikes, E-Cars, Carshare, Bikeshare, and Micro-EVs in China have shaken up the traditional motorization pathways that have occurred in developing countries in the past. The combination of emerging vehicle technologies, urban and environmental constraints, and heavy-handed policy make China's motorization processes unique in the world—but how China motorizes has far-reaching impacts based on sheer volume of vehicles and population.

This seminar discusses the results of a six-year NSF CAREER project to explore China's motorization processes, combining behavioral and environmental modeling approaches to assess the impacts of emerging vehicle technologies on motorization and ultimately environmental sustainability. The focus is mostly on …

Comparing Automated Shared Taxis And Conventional Bus Transit For A Small City, Louis A. Merlin

Journal of Public Transportation

This study compared two hypothetical transit scenarios with the current bus transit system for serving the transit passengers of Ann Arbor, Michigan, for a typical fall weekday in 2013. One scenario consists of an automated taxi system that allows only one rider at a time, and the other consists of a similar automated taxi system that allows ridesharing for up to four passengers. The two automated taxi scenarios were modeled on simulated transit passenger travel demand data via agent-based models. All three scenarios were then compared for their level of service, cost, greenhouse gas emissions, and congestion impacts. The automated …

Measuring The Impacts Of Social Media On Advancing Public Transit, Jenny H. Liu, Xuegang Ban, O. A. Elrahman

TREC Final Reports

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 …

Focusing On Equity In Regional Plans, Kristine M. Williams

TREC Project Briefs

Metropolitan planning organizations (MPOs) have long been required to consider the equity implications of their regional transportation plans and processes.

Augmenting Decisions Of Taxi Drivers Through Reinforcement Learning For Improving Revenues, Tanvi Verma, Pradeep Varakantham, Sarit Kraus, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

Taxis (which include cars working with car aggregation systems such as Uber, Grab, Lyft etc.) have become a critical component in the urban transportation. While most research and applications in the context of taxis have focused on improving performance from a customer perspective, in this paper,we focus on improving performance from a taxi driver perspective. Higher revenues for taxi drivers can help bring more drivers into the system thereby improving availability for customers in dense urban cities.Typically, when there is no customer on board, taxi driverswill cruise around to find customers either directly (on thestreet) or indirectly (due to a …

Denoising Autoencoders For Fast Real-Time Traffic Estimation On Urban Road Networks, Soham Ghosh, Muhammad Tayyab Asif, Laura Wynter

Research Collection School Of Computing and Information Systems

We propose a new method for traffic state estimation applicable to large urban road networks where a significant amount of the real-time and historical data is missing. Our proposed approach involves estimating the missing historical data through low-rank matrix completion, coupled with an online estimation approach for estimating the missing real-time data. In contrast to the traditional approach, the proposed method does not require re-calibration every time new streaming data becomes available. Empirical results from two metropolitan cities show that the proposed two-step approach provides comparable accuracy to a state of the art benchmark method while achieving two orders of …

Tackling Large-Scale Home Health Care Delivery Problem With Uncertainty, Cen Chen, Zachary Rubinstein, Stephen Smith, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

In this work, we investigate a multi-period Home HealthCare Scheduling Problem (HHCSP) under stochastic serviceand travel times. We first model the deterministic problemas an integer linear programming model that incorporatesreal-world requirements, such as time windows, continuityof care, workload fairness, inter-visit temporal dependencies.We then extend the model to cope with uncertainty in durations,by introducing chance constraints into the formulation.We propose efficient solution approaches, which providequantifiable near-optimal solutions and further handlethe uncertainties by employing a sampling-based strategy. Wedemonstrate the effectiveness of our proposed approaches oninstances synthetically generated by real-world dataset forboth deterministic and stochastic scenarios.

Analyzing The Impact Of Public Transit Usage On Obesity, Zhaowei She, Douglas M. King, Jacobson Sheldon Sheldon

Research Collection Lee Kong Chian School Of Business

The objective of this paper is to estimate the impact of county-level public transit usage on obesity prevalence in the United States and assess the potential for public transit usage as an intervention for obesity. This study adopts an instrumental regression approach to implicitly control for potential selection bias due to possible differences in commuting preferences among obese and non-obese populations. United States health data from the 2009 Behavioral Risk Factor Surveillance System and transportation data from the 2009 National Household Travel Survey are aggregated and matched at the county level. County-level public transit accessibility and vehicle ownership rates are …

Breaking Barriers To Bike Share: Insights From Residents Of Traditionally Underserved Neighborhoods, Nathan Mcneil, Jennifer Dill, John Macarthur, Joseph Broach, Steven Howland

TREC Final Reports

Evidence has shown that higher income and white populations are overrepresented in both access to and use of bike share. Efforts to overcome underserved communities’ barriers to access and use of bike share have been initiated in a number of cities, including those working with the Better Bike Share Partnership (BBSP) to launch and test potentially replicable approaches to improve the equity outcomes. This report describes findings from a survey of residents living near bike share stations placed in underserved communities of select BBSP cities: Philadelphia, Chicago, and Brooklyn. These were neighborhoods targeted for focused outreach related to BBSP programs, …

What Do Americans Think About Federal Tax Options To Support Public Transit, Highways, And Local Streets And Roads? Results From Year Eight Of A National Survey, Asha Weinstein Agrawal, Hilary Nixon

Mineta Transportation Institute

This report summarizes the results of the eighth year of a national random-digit-dial public opinion poll asking 1,201 respondents if they would support various tax options for raising federal transportation revenues, with a special focus on understanding support for increasing revenues for public transit. Ten specific tax options tested were variations on raising the federal gas tax rate, creating a new mileage tax, and creating a new federal sales tax. Other questions probed perceptions related to public transit, including knowledge and opinions about federal taxes to support transit. In addition, the survey collected data on standard sociodemographic factors, travel behavior …

Online Repositioning In Bike Sharing Systems, Meghna Lowalekar, Pradeep Varakantham, Supriyo Ghosh, Sanjay Dominic Jena, Patrick Jaillet

Research Collection School Of Computing and Information Systems

Due to increased traffic congestion and carbon emissions, Bike Sharing Systems (BSSs) are adopted in various cities for short distance travels, specifically for last mile transportation. The success of a bike sharing system depends on its ability to have bikes available at the "right" base stations at the "right" times. Typically, carrier vehicles are used to perform repositioning of bikes between stations so as to satisfy customer requests. Owing to the uncertainty in customer demand and day-long repositioning, the problem of having bikes available at the right base stations at the right times is a challenging one. In this paper, …

Understanding The Role Of Driver, Vehicle, Environment, And Policy Factors In Crash Injury Severity Among Older Adults In The United States, Chae Man Lee

Graduate Doctoral Dissertations

Driving is related to quality of life and health outcomes. Older drivers involved in car crashes have a higher risk of experiencing a severe injury or fatality. Understanding factors related to injury severity may identify points of intervention to promote road safety. The purpose of this study is to investigate how individual characteristics, vehicle elements, environmental elements, and driving licensing policy are associated with level of injury severity from no injury to fatal injury resulting from car crashes. Furthermore, this dissertation research utilizes the Geographic Information System (GIS) process to visualize the location of crashes and to identify the hot …

Annual Metro Regional Trail Count And Why Local Extrapolation Factors Matter, Geoff Gibson

PSU Transportation Seminars

Metro, Portland's regional governing agency, conducts annual two-hour counts along its regional trail every September. This upcoming fall (2017) will be the 10th year that the counts have been held, which means we at Metro can finally start seeing noticeable, long-lasting trends in the regional trail network. Perhaps more importantly, we are seeing how these data have directly impacted investments in future trail, bicycle, and pedestrian projects.

This seminar will cover the history of the program, details of how it's conducted and why it's conducted that way, how data are used (including an inside look at future iterations of Metro's …