Francois Dion

• University of California, Berkeley

Transit signal priority (TSP) is an operational control strategy that provides preferential treatments for transit vehicles at signalized intersections. Many transit agencies are currently considering the implementation of priority systems providing buses with preferential treatments at signalized intersections. While studies have demonstrated pote...

This chapter reports on the chain of collisions that occur in case of emergency deceleration in a platoon of vehicles driving in a convoy. Chain Collision Avoidance applications are a new emerging means of reducing the number of chain accidents on the road by providing cars with collaborative communication capabilities, thus allowing them to react...

Recent developments in vehicle onboard computers and vehicle-to-vehicle communications technology allow automatic control of vehicles and the organization of vehicles into platoons with short intraplatoon distances. One of the major issues with platoon control is latency in wireless communications. Latency has a negative impact on safety and disrup...

In an attempt to bridge the gap between less accurate macroscopic models and data intensive microscopic emission models, the paper presents a modal model that estimates light-duty vehicle fuel consumption and emission rates on a link-by-link basis using three independent variables, namely the average speed, the number of vehicle stops per unit dist...

This paper presents an effort to develop a virtual testbed for assessing probe vehicle data generation by IntelliDrive vehicles within a microscopic traffic-simulation environment. Simulation capabilities are implemented through the development of a portable plug-in module using the application programming interface of the Paramics microscopic traf...

Traffic congestion frequently occurs during rush hour periods and in work zones, and can account for a significant share of vehicle emissions and air quality impacts. This study estimates vehicle emissions from light- and heavy-duty vehicles (LDVs, HDVs) in work zone and rush hour congestion, which are compared to emissions under free-flow traffic...

This paper presents a generalized framework for integrating a wireless network simulator and a vehicle traffic simulator for rapid prototyping and evaluation of Dedicated Short Range Communication (DSRC) based vehicular communication protocols and their applications in the context of Intelligent Transportation System (ITS). A novel method of inter-...

This paper assesses various issues associated with the use of IntelliDrive probe vehicle data generated according to existing protocols. These evaluations are conducted using a virtual IntelliDrive probe vehicle data generator implemented within the Paramics microscopic traffic simulation model. Issues investigated included the ability to monitor q...

Three studies aimed at investigating effects of roadway air pollutants in Detroit, Michigan are reviewed. The "Detroit Asthma Morbidity, Air Quality and Traffic Study", examines whether healthcare utilization for severe respiratory events are associated with air pollutant concentrations and locations of emission sources, including highways. The "Ro...

This paper presents a microscopic traffic simulation model that has been developed to assist in the design of Intelligent Transportation System applications relying on wireless transmissions to obtain data critical to their operation. This model, which is derived from the Intelligent Driver Model open-source traffic simulation model, implements rou...

Many transit agencies are currently considering implementing priority systems providing buses with temporary green signal extensions and early green recalls. While many studies have demonstrated a potential for bus delay reduction and negative traffic impacts, very few have addressed the problems posed by variable dwell times at nearside bus stops....

Many transit agencies are currently considering the implementation of priority systems providing buses with temporary green signal extensions and early green recalls at signalized intersections. While many studies have demonstrated potential delay reductions for buses and potential negative impacts on traffic, none attempted to formally quantify th...

This study focuses on the problem of unlawful left-lane usage on non-congested two-lane rural freeways in Michigan. According to the Michigan Vehicle Code, vehicles shall remain on the right lane of two-lane sections of rural freeways when not passing other vehicles. While drivers are currently reminded of this rule by signs stating “Slower Traffic...

The paper describes a low-pass adaptive filtering algorithm for predicting average roadway travel times using automatic vehicle identification (AVI) data. The algorithm is unique in three aspects. First, it is designed to handle both stable (constant mean) and unstable (varying mean) traffic conditions. Second, the algorithm can be successfully app...

The estimation of path or trip travel-time reliability is critical to any advanced traveler information system. The state-of-practice procedures for estimating path travel-time reliability assumes that travel times follow a normal distribution and requires a measure of trip travel-time variance. The study analyzes AVI data from San Antonio and demo...

This article presents an overview of highway cooperative collision avoidance (CCA), which is an emerging vehicular safety application using the IEEE- and ASTM-adopted Dedicated Short Range Communication (DSRC) standard. Along with a description of the DSRC architecture, we introduce the concept of CCA and its implementation requirements in the cont...

Recently, increasing attention has been put on the use of automated vehicle control systems to reduce traffic crashes due to driver errors. Proposed systems rely on either onboard range sensors or vehicle-to-vehicle wireless communications to obtain pertinent information about surrounding vehicles and to determine appropriate acceleration or decele...

Recently, increasing attention has been put on the use of automated vehicle control systems to reduce traffic crashes due to driver errors. Proposed systems rely on either onboard range sensors or vehicle-to-vehicle wireless communications to obtain pertinent information about surrounding vehicles and to determine appropriate acceleration or decele...

In efforts to reduce traffic accidents and improve the efficient utilization of existing transportation networks, increasing attention is being given to the use of wireless communications between vehicles and road-side equipment to develop new intelligent transportation system (ITS) applications that can help improve the safety of transportation ne...

In efforts to reduce traffic accidents and improve the efficient utilization of existing transportation networks, increasing attention is being given to the use of wireless communications between vehicles and roadside equipment to develop new intelligent transportation system (ITS) applications that can help improve the safety of transportation net...

This paper proposes a broadcast based packet forwarding mechanism for intra-platoon cooperative collision avoidance (CCA) using dedicated short range communication (DSRC) links. The paper first motivates the needs for broadcast forwarding as opposed to unicast routing for transporting inter-vehicle data for safety-critical applications. Then it int...

This paper presents the findings of a study evaluating the potential benefits of implementing transit signal priority along the Columbia Pike arterial corridor, in Arlington, Va. The study uses the INTEGRATION microscopic traffic simulation model to evaluate the impact of a number of alternative priority strategies on both the prioritized buses and...

Delay is an important parameter that is used in the optimization of traffic signal timings and the estimation of the level of service at signalized intersection approaches. However, delay is also a parameter that is difficult to estimate. While many methods are currently available to estimate the delays incurred at intersection approaches, very lit...

6,474 (words) + 1000 (tables + figures) = 7,474 words ABSTRACT This paper presents and validates a vehicle dynamics model for predicting maximum light-duty vehicle accelerations for use within a microscopic traffic simulation environment. The research also constructs a database of unconstrained vehicle acceleration data for 13 light-duty vehicles a...

The paper presents a simulation study evaluating the impacts of alternative transit priority strategies along the Columbia Pike arterial in Arlington, Virginia, for both the AM peak and midday travel periods. The priority logic that is considered provides simple green extensions and green recalls within a fixed-time traffic signal control environme...

At-grade highway-railroad crossings cause traffic control problems that have a bearing not only on traffic safety but also on traffic flow efficiency. Crossings located near freeway exits pose particularly acute problems, as long closures could result in vehicle queues that spill back onto freeway lanes. A potential solution to this problem is eval...

Recent progress in technology has facilitated the design, testing, and deployment of traffic signal priority strategies for transit buses. However, a clear consensus has not emerged about the evaluation of these strategies. Each agency implementing these strategies can have differing goals, and there are often conflicting issues, needs, and concern...

The automated vehicle identification (AVI) equipment location problem entails determination of the best locations for the automated vehicle identification equipment. The paper attempts to solve the AVI equipment location problem as a multi-objective optimization problem, thus determining the best locations on the basis of several criteria. The deve...

Previous experience has shown that real-time, traffic-responsive signal control has the ability to improve traffic operations in urban areas when compared to traditional fixed-time control. However, most of these experiences have focused primarily on the impact on private automobiles. This paper describes the development and evaluation of a fully d...

Traffic-operational projects typically are evaluated by using several measures of effectiveness, including vehicle delay, queue sizes, and vehicle stops. Other emerging measures include vehicle fuel consumption and emissions. Although these emerging measures are difficult to determine in the field, they can be estimated by using second-by-second sp...

ABSTRACT This paper first reviews state-of-practice models ,for estimating vehicle stops at signalized intersections and then introduces two approaches ,for computing ,vehicle stops at under-saturated and ,over-saturated signalized intersections. The first approach that is introduced is a microscopic model that computes instantaneous partial and fu...

Some insight into the potential benefits of coordinating traffic signals across jurisdictional boundaries by using as a case study the Scottsdale Road-Rural Road corridor in the Arizona cities of Tempe and Scottsdale is provided. In particular, the feasibility of using second-by-second speed measurements from Global Positioning System-equipped vehi...

Many problems in electrocatalysis involve distribution of adsorption energies. Similarly, electrochemical impedance spectroscopy often involves distributed elements. Such problems are described by Fredholm integral equations and the underlying distribution functions may be solved using regularization techniques. A software package developed recentl...

Real-time traffic signal optimization software was developed using object-oriented techniques based upon the SPPORT (Signal Priority Procedure for Optimization in Real Time) model. SPPORT is a rule-based model that provides specialized mechanisms for transit priority. Based upon a flexible discrete-event traffic simulator that realistically models...

Urban traffic characteristics are examined along with the various available current approaches to controlling traffic efficiently at signalized intersections. Fixed-time, central, and distributed real-time control approaches are considered. It is determined that the best method of control varies with network and flow conditions. It is concluded tha...

This paper examines and compares the approaches to real-time control of signalised networks with reference to the prototype models that use them. By knowing the philosophy behind each approach, one can attain a basic understanding of what the corresponding model attempts to achieve and how. The paper considers SCOOT, PRODYN, UTOPIA, SCATS, OPAC, an...

Urban traffic characteristics are examined along with the various available current approaches to controlling traffic efficiently at signalized intersections. Fixed-time, central, and distributed real-time control approaches are considered. It is determined that the best method of control varies with network and flow conditions. It is concluded tha...

The Phoenix Metropolitan Model Deployment Initiative (MMDI) is a seven-year project that attempts to develop and integrate intelligent transportation systems for the Phoenix Metropolitan area. As part of this project, this paper provides some insight as to the potential benefits of coordinating traffic signals across jurisdictional boundaries along...

Real-time network signal control offer the potential to provide delay benefits over traditional fixed time and actuated control. The SPPORT (Signal Priority Procedure for Optimization in Real-Time) model is a fully distributed heuristic rule-based signal control method that explicitly considers transit priority. While a distributed architecture ena...

The paper describes an algorithm that was developed for estimating reliable and accurate average roadway link travel times using Automatic Vehicle Identification (AVI) data. The algorithm presented is unique in two aspects. First, it is designed to handle both steady state (mean constant) and transient (varying mean) traffic conditions. In particul...

Thesis (Ph. D.)--University of Waterloo, 1999. Includes bibliographical references.

Thèse (M. Sc. A.)--École polytechnique de Montréal, 1994. Comprend des réf. bibliogr.

This report covers several key subjects related to the generation of IntelliDriveSM probe vehicle data and use of this data in application of interest to state departments of transportation and local public transportation agencies. The evaluations conducted as part of this project are primarily based on the probe vehicle data collection system that...