Traffic Operations and Management

Evaluating Alternative Measures of Bicycling Level of Traffic Stress Using Crowdsourced Route Satisfaction Data

Harvey, C
Fang, K
Rodriguez, D
2019

Approaches for evaluating the quality of bicycling have become increasingly important for planning bicycle infrastructure improvements. Mekuria, Furth, and Nixon’s (2012) “Level of Traffic Stress” (LTS) approach, which requires minimal data inputs and produces a simple and intuitive output, has emerged as a widely-used framework for identifying streets that are “low-stress” for cyclists. The LTS framework is based on a hierarchy of characteristics, largely related to traffic speed and roadway layout, that are presumed to cause higher or lower levels of stress. Despite the apparent...

Support for Market-based and Command-and-Control Congestion Relief Policies in Latin American Cities: Effects of Mobility, Environmental Health, and City-level Factors

Wang, X
Rodriguez, D
Mahendra, A
2021
Public support for the implementation of congestion relief policies is critical for the policies’ technical and political success. To identify the personal, social, and city-level factors associated with higher acceptance towards such policies, this study uses a 2016 survey of 8178 residents from 11 cities across 10 Latin American countries collected by the Development Bank of Latin America (Corporación Andina de Fomento or CAF). We examined support for two demand-side approaches to managing the traffic congestion externality: congestion pricing – a market-based approach, and driving...

Accessibility, Mobility, and Transportation Innovations in Latin America and the Caribbean: Successes and Areas for Improvement

Rodriguez, Daniel
2022

High traffic congestion and travel times in the cities of Latin America and the Caribbean have significant impacts on air quality, population health, and well-being. To address these challenges, policy and infrastructure innovations have been proposed and implemented over recent decades. This chapter reviews the current state of mobility and accessibility in the region, with special attention to innovative practices and their impacts on accessibility, especially for low-income populations. Specifically, bus rapid transit and aerial tram infrastructure as well as policy innovations such as...

Empirical Analysis of Traffic Breakdown Probability Distribution with Respect to Speed and Occupancy

Chow, Andy H.F.
Lu, Xiao-Yun
Qiu, Tony Z.
2009

From an operation viewpoint, traffic breakdown (from free-flow) was defined as when the average speed of traffic drops below a certain threshold. It is known that traffic breakdown is a stochastic phenomenon which can happen even when the traffic flow is below the capacity. The capacity has many definitions, such as that in HCM or the average of maximum daily flow. This study investigates the probability of breakdown at certain locations of freeway. The motivation is to find a practical capacity for each freeway section for active traffic control/operation purposes, which could be...

Alternative Traffic Signal Illumination

Cohn, Theodore E.
Greenhouse, Daniel
Knowles, Richard
1998

New technologies have enabled the production of traffic signals that have significant advantages over standard incandescent signals, including greater energy efficiency and lower maintenance costs. Before the new signals are installed in the field, it is important to assure that they as visible as the older signals. We have developed a quality index we term the usability factor (UF) which can be used to evaluate the visibility of a new device relative to that of a standard reference lamp. We have measured UF's of a variety of new types of lamps by means of heterochromatic flicker...

Extracting More Information from the Existing Freeway Traffic Monitoring Infrastructure

Coifman, Benjamin
2006

This report presents the results of TO 5302, Extracting More Information from the Existing Freeway Traffic Monitoring Infrastructure. This report represents significant advances in the PATH sponsored research into vehicle reidentification from conventional loop detectors, first by extending the methodology across major merge and diverge freeway sections. Second, it extends the methodology to single loop detectors. The report also extends the understanding of traffic phenomena impacting both traffic flow and the performance of the reidentification algorithms. It examines the impacts of lane...

Hybrid Data Implementation: Final Report for Task Number 3643

Khan, Sakib Mahmud, PhD
Fournier, Nicholas, PhD
Mauch, Michael, PhD
Patire, Anthony D, PhD
Skabardonis, Alex, PhD
2020

This report investigates how Caltrans may incorporate third-party vendor data into its established system for performance measurement to improve accuracy of vehicle hours of delay (VHD) estimates and to enable smarter deployment of point-based sensors, such as loops. Methods are evaluated to project data from multiple sources, including multiple vendors and internal data feeds, onto the same domain of analysis so as to compute performance metrics with high fidelity. The recommended VHD estimation method depends on the infrastructure type and the data available. Overall a hybrid approach...

Using Cooperative Adaptive Cruise Control (CACC) to Form High-Performance Vehicle Streams:Simulation Results Analysis

Liu, Hao
Kan, Xingan (David)
Shladover, Steven E.
Lu, Xiao-Yun
2018

This document contains detailed simulation results analysis and discussion for the Federal Highway Administration (FHWA) Exploratory Advanced Research (EAR) project entitled Using Cooperative Adaptive Cruise Control (CACC) to Form High-Performance Vehicle Streams. The objective of this study is to obtain authoritative predictions of traffic impacts of ACC and CACC at various market penetrations and define the CACC operation strategies that create the most capacity and throughput improvement in the freeway traffic stream. A microscopic traffic simulation environment has been developed for...

Enhancements To A Simulation Framework For Analyzing Urban Traffic Networks With Atis/atms

Jayakrishnan, R.
Rathi, U.
Rindt, C.
Vaideeshwaran, G.
1996

This report focuses on the DYNASMART simulation program presents a model that is capable of simulating large urban networks under various Advanced Traffic Management Systems (ATMS) and Advanced Traveler Information Systems (ATIS) strategies. It includes modules for driver responses to information and for capturing the dynamics of the network paths. The research also included the simulation study of a network in Orange County, California, where the benefits from candidate ATIS and ATMS strategies were evaluated. The DYNASMART model has evolved into a flexible tool that can be applied to...

Spatial and Temporal Utility Modeling to Increase Transit Ridership

Church, Richard L.
Noronha, Val
Lei, Ting
Corrigan, Wils
Burbidge, Shaunna
Marston, Jim
2005

The objective of this research project was to develop a better understanding of the possible alternatives that a large employment center, like the University of California at Santa Barbara, can adopt in order to better utilize transit, mitigate traffic, and reduce demand for on-site parking. Although this project was oriented to the UCSB campus, the techniques and approaches developed in this project were designed to be equally applicable elsewhere. There were three major elements of this project: 1) develop an understanding of commuting employees through the use of a survey, 2) identify...