Social and Behavioral Sciences Commons^™

Network Effects Of Disruptive Traffic Events, Juan Medina, Xiaoyue Cathy Liu

TREC Final Reports

Current traffic management strategies are based on expected conditions caused by recurring congestion (e.g., by time of day, day of week), and can be very effective when provisions are also given for reasonable variations from such expectations. However, traffic variations due to non-recurrent events (e.g., crashes) can be much larger and difficult to predict, making also challenging efforts to identify, measure, and forecast their disruptive effects. This project explores a proactive approach to deploy a tool for managing non-recurrent congestion by identifying and quantifying the effects of disruptive traffic events at a microscopic level using a comprehensive set of data …

Traffic Signal Consensus Control, Gerardo Lafferriere

TREC Final Reports

We introduce a model for traffic signal management based on network consensus control principles. The underlying principle in a consensus approach is that traffic signal cycles are adjusted in a distributed way so as to achieve desirable ratios of queue lengths throughout the street network. This approach tends to reduce traffic congestion due to queue saturation at any particular city block and it appears less susceptible to congestion due to unexpected traffic loads on the street grid. We developed simulation tools based on the MATLAB computing environment to analyze the use of the mathematical consensus approach to manage the signal …

A Decentralized Network Consensus Control Approach For Urban Traffic Signal Optimization, Gerardo Lafferriere

TREC Project Briefs

Automobile traffic congestion in urban areas is a worsening problem that comes with significant economic and social costs. This report offers a new approach to urban congestion management through traffic signal control.

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 …

Avoiding Bus Bunching: From Theory To Practice, Ricardo Giesen

PSU Transportation Seminars

The problem of bus bunching in a high frequency service has been largely studied in the literature.

This phenomenon is produced by three main factors

(i) the variability in travel time between stops; (ii) variations in passenger demand; and (iii) drivers’ heterogeneity.

In order to tackle this phenomenon a wide range of control strategies have been proposed, however, none of them had been successfully implemented on a large transit network with high frequency services.

In this talk, we present a control scheme based on a rolling horizon optimization problem that has been successfully implemented for real-time control of two high …

Leveraging Signal Infrastructure For Non-Motorized Counts In A Statewide Program: A Pilot Study, Bryan Philip Blanc

PSU Transportation Seminars

Transportation agencies are beginning to explore and develop non-motorized counting programs. This paper presents the results of a pilot study testing the use of existing signal infrastructure – 2070 signal controllers with advanced software to log pedestrian phase actuations and detections from bicycle lane inductive loops – to count pedestrians and bicycles. The pilot study was conducted at a typical suburban signalized intersection with heavy motorized traffic that was instrumented on all four approaches with pedestrian push buttons and advance inductive loops in the bicycle lane for signal operation. One day (24 hours) of video data were collected as ground …

Modeling And Analyzing The Impact Of Advanced Technologies On Transit Performance Measures In Arterial Corridors, Miguel A. Figliozzi, Wei Feng

Civil and Environmental Engineering Faculty Publications and Presentations

Transportation and transit agencies have implemented advanced technologies like transit signal priority (TSP) and Sydney Coordinated Adaptive Traffic System (SCATS) to reduce travel times and improve reliability. However, due to the lack of detailed empirical data, the joint impact of these factors and improvement strategies on bus travel time has not been studied at the stop-to-stop segment level. With the aim of assessing the performance of an existing TSP/SCATS system, this study had access to a unique set of high-resolution bus and traffic signal data. Novel algorithms and performance measures to measure TSP performance are proposed. Results indicate that a …

Evaluation Of Advanced Traffic Control Systems, Miguel Figliozzi

TREC Project Briefs

Researchers from Portland State University develop performance measures and algorithms for evaluation of state-of-the-art traffic signal control technologies..

Exploring The Effects Of Adaptive Traffic Systems, Miguel A. Figliozzi, Christopher M. Monsere

TREC Project Briefs

Researchers conduct an in-depth analysis of traffic performance and associated vehicular emissions, before and after the installation of a SCATS unit.

Improved Pedestrian Safety At Signalized Intersections Operating The Flashing Yellow Arrow, David Hurwitz, Christopher M. Monsere

TREC Final Reports

In some jurisdictions, protected left-turn phasing has been replaced with the flashing yellow arrow (FYA) for protected/permissive left turns (PPLTs) to reduce delay. However, it is important to have a thorough understanding of the conflict between pedestrians and the permissive left-turning vehicle. This presentation summarizes the results of research conducted with a high-fidelity, motion-based driving simulator and mobile eye-tracking equipment to study the effects of the opposing traffic, the presence and walking direction of pedestrians, and the number of section heads to display the FYA on driver performance. To accomplish this research, a six-intersection simulated environment was created. In total, …

A Study Of Headway Maintenance For Bus Routes: Causes And Effects Of “Bus Bunching” In Extensive And Congested Service Areas, Miguel A. Figliozzi, Wu-Chi Feng, Gerardo Lafferriere, Wei Feng

Civil and Environmental Engineering Faculty Publications and Presentations

A healthy and efficient public transit system is indispensable to reduce congestion, emissions, energy consumption, and car dependency in urban areas. The objective of this research is to 1) develop methods to evaluate and visualize bus service reliability for transit agencies in various temporal and spatial aggregation levels; 2) identify the recurrent unreliability trends of bus routes (focusing on high-frequency service periods) and understand their characteristics, causes and effects; and 3) model service times using linear regression models.

This research utilized six months of archived automatic vehicle location (AVL) and automatic passenger count (APC) data from a low-performance route (Route …