Traffic Operations and Management

Approximate Method To Determine The Worst Case Performance Of A Nonlinear Dynamical System

Tongue, Benson H.
Packard, Andrew
1998

This report presents the theoretical development of a method to evaluate differing platoon control strategies and determine each strategy's worst case behavior under bounded parametric variations. The approach is useful in aiding a platoon designer in determining the robustness a design strategy is in the face of system uncertainties. Index Terms: traffic platooning // safety // automated highways // vehicle dynamics.

Vehicles as Probes

Sanwal, Kumud K.
Walrand, Jean
1995

In this paper, the authors discuss the use of vehicles moving in traffic as probes that provide data for estimation and prediction of traffic behavior. The probe vehicles can report data on their speeds, locations, or travel times which can be used by an algorithm that updates estimates of traffic state and makes predictions for the future. The authors address some of the key issues involved in the design of such a traffic monitoring system.

Vehicle Navigation and Route Guidance Technologies: Push and Pull Factors Assessment

Ygnace, Jean-luc
Lavallee, Paul
Al-Deek, Haitham M.
1990

This study focusses on the development of navigation and route guidance technologies with an emphasis on existing systems, industrial strategies, market approach and human factors considerations. By considering the different situations in the US, Europe, and Japan the report analyzes the conditions under which one reasonably could assume a wide spread of these technologies with social and individual benefits.

Using Input-Output Diagram to Determine Spatial and Temporal Extents of a Queue Upstream of a Bottleneck

Lawson, Tim W.
Lovell, David J.
Daganzo, Carlos F.
1997

A simple approach is described for modifying an input-output (or queue-ing) diagram to measure the time and distance spent by vehicles in a queue in a much simpler and self-serving manner than a time-space diagram. The graphic technique requires construction of a curve depicting the cumulative number of vehicles to have reached the back of the queue as a function of time, but, as indicated here, the technique can be easily automated with a spreadsheet. The technique is applied to the simple case of a constant departure rate from a bottleneck and to the slightly more general case of a...

Using Cooperative Adaptive Cruise Control (CACC) to Form High-Performance Vehicle Streams. Definitions, Literature Review and Operational Concept Alternatives

Shladover, Steven E.
Nowakowski, Christopher
Lu, Xiao-Yun
2018

Cooperative Adaptive Cruise Control (CACC) is a term that has been used rather loosely in recent years, such that different people visualize different functions and capabilities when discussing CACC systems. Thus, there are now multiple system concepts that have been described under the CACC label, and the functionalities included in these varied concepts can be quite different from each other. At the heart of each CACC concept is the merging of Adaptive Cruise Control (ACC), a subset of the broader class of automated speed control systems, with acooperative element, such a Vehicle-to-...

Unified Automatic Control of Vehicular Systems with Reinforcement Learning

Yan, Zhongxia
Kreidieh, Abdul Rahman
Vinitsky, Eugene
Bayen, Alexandre M.
2023

Emerging vehicular systems with increasing proportions of automated components present opportunities for optimal control to mitigate congestion and increase efficiency. There has been a recent interest in applying deep reinforcement learning (DRL) to these nonlinear dynamical systems for the automatic design of effective control strategies. Despite conceptual advantages of DRL being model-free, studies typically nonetheless rely on training setups that are painstakingly specialized to specific vehicular systems. This is a key challenge to efficient analysis of diverse vehicular and...

Two Proposals to Improve Freeway Traffic Flow

Karaaslan, Ufuk
Varaiya, Pravin
Walrand, Jean
1990

The following two proposals are presented: (1) Vehicles are organized in platoons in which the lead car is manually driven and the other cars are under automatic spacing (headway) control. A plausible model of the resulting flow of traffic indicates that, for an average platoon size of 20, the capacity of the freeway increases by a factor of four. (2) A macroscopic model of freeway traffic congestion along with a control law for reducing congestion is presented. Simulation of the resulting closed loop model indicates a dramatic reduction in congestion.

Turning Movement Estimation in Real Time (TMERT)

Martin, Peter T.
1995

This report describes the development of a new model that can monitor system performance and derive management and control strategies in real time. It presents the TMERT (Turning Movement Estimation in Real Time) model, a method of estimating turning movement flows from link detected flows at small recurrent intervals, in real time.

TravInfo Evaluation (Technology Element) Traveler Information Center (TIC) Study (September 1996 - June 1997)

Miller, Mark A.
Loukakos, Dimitri
1998

TravInfo is a Field Operational Test of advanced traveler information systems for the San Francisco Bay Area, sponsored by the Federal Highway Administration (FHWA). The project involves a public/private partnership which seeks to compile, integrate and broadly disseminate timely and accurate multi-modal traveler information through commercial products and services. The public sector component centers on the Traveler Information Center (TIC), which collects and integrates both static and dynamic traveler information. The TIC began operations in September 1996 and will operate as an FOT...

Traffic Management Systems Performance Measurement: Final Report

Banks, James H.
Kelly, Gregory
1997

This report documents a study of performance measurement for Transportation Management Centers (TMCs). Performance measurement requirements were analyzed, data collection and management techniques were investigated, and case study traffic data system improvement plans were prepared for two Caltrans districts.