Traffic Operations and Management

Evaluation of Coordinated Ramp Metering (CRM) Systems in California

Mauch, Michael
Skabardonis, Alexander
2021

Freeway on-ramp metering (RM) has been extensively used as a traffic control strategy to regulate the entry of the on-ramp vehicles to prevent congestion at the freeway merging areas and preserve the freeway capacity. Benefits of RM include improved freeway travel times, improved travel time reliability, and accident reductions. Fixed-rate ramp metering strategies are based on historical data and implemented by time of day. Traffic responsive RM strategies are based on real time freeway traffic data provided by loop detectors at the vicinity of the on-ramp. Coordinated RM determine the...

Model of Human Vehicle Driving - a Predictive Nonlinear Optimization Approach

Prokop, Günther
2000

When driving a vehicle the human acts as a controller in a highly dynamic environment. Thus human behavior in that control loop has to a large extent been described using control theoretical methodology. We develop a driver model, in which driving is seen as a model predictive control task in such a way that the driver accumulates knowledge about his/her vehicle's handling properties. He/she builds a model out of that knowledge and uses it to predict the vehicle's future reactions on his/her control inputs. The human's behavioral optimization is reflected in the driver model by using that...

Methods to Address Headlight Glare

Christianson, Kent B.
Greenhouse, Daniel S.
Barton, Joseph E.
Chow, Christina
2009

The goal of this project was to design, implement, and validate a computerized Glare Meter Tool that could be used in the field to assess the level of glare from headlights of opposing vehicles in a variety of situations, without relying on subjective reports of observers. Both disability glare and discomfort glare were addressed. The net result is an instrument that is capable of acquiring an image of a scene with glare, then analyzing the image to output a number on the standard, widely-used De Boer Rating Scale for Evaluation of Discomfort Glare, and also an equivalent veiling luminance...

Model Selection And Initial Application Of CONTRAM Model For Evaluating In-vehicle Information Systems

Gardes, Yonnel
Haldors, Bruce
May, Adolf D.
1991

The objectives of this study were to select a traffic assignment and simulation model, apply that model to an integrated freeway/arterial network such as the Smart Corridor in Los Angeles, California, and, using the model, make an initial evaluation of in-vehicle information systems and the applicability of the model.

Ventura/Lompoc Smart Card Demonstration Evaluation: Final Report Volume 1 Technical Performance, User Response, and Institutional Analysis

Giuliano, Genevieve
Moore, II, James E.
Golob, Jacqueline
1999

This report presents evaluation results of the Smart Card Phase III FieldDemonstration. Its purpose is to demonstrate the feasibility of using Smart Cards and othertechnology to provide an integrated fare medium across several transit operators. TheDemonstration took place from May 1995 through June 1997, and it was located in VenturaCounty, California. Participants included seven transit agencies, with the Ventura CountyTransportation Commission acting as the lead local agency. The technology deployed is anintegrated fare transaction and vehicle management/monitoring system, termed...

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...