Roads/Highways

Assessing Automated Speed Enforcement in California

Chan, Ching-Yao
Li, Kang
Lee, Joon-Ho
2010

Speeding is known to be related to a significant portion of highway collisions. As part of the efforts to seek safety improvements of the California highway network, the California Department of Transportation (Caltrans) is exploring the implementation issues of automated speed enforcement (ASE). This report provides an overview of Task Order 6212 undertaken by California PATH to assess various issues associated with ASE systems.An ASE system designed for use in work zones was acquired and tested in several field experimental sites, along with several other commercially-off-the-shelf...

ITS Band Roadside to Vehicle Communications in a Highway Setting

Dickey, Susan
Dulmage, Jared
Huang, Ching-Ling
Sengupta, Raja
2010

Researchers investigated the testing and evaluation of radio and communication protocol standards for the 5.9 GHz spectrum that has been approved by the Federal Communications Commission for exclusive transportation use. This spectrum allocation is intended for use as Dedicated Short Range Communications (DSRC) in the context of high-value Intelligent Transportation Systems (ITS) applications. In this report, we summarize the Wireless Access in a Vehicular Environment (WAVE) standardization effort for 5.9 GHz DSRC, its current status, and related issues of the IEEE 802.11p and IEEE 1609...

Traffic Flow Control In Automated Highway Systems

Alvarez, Luis
Horowitz, Roberto
1997

This report studies the problem of traffic control in the Automated Highway System (AHS) hierarchical architecture of the California PATH program. A link layer controller for the PATH AHS architecture is presented. It is shown that the proposed control laws stabilize the vehicular density and flow around predetermined profiles.

Evaluation of the Anaheim Advanced Traffic Control System Field Operational Test: Executive Summary

McNally, M. G.
Moore, James E., II
MacCarley, C. Arthur
Jayakrishnan, R.
1999

This Executive Summary provides an overview of the technical and institutional issues associated with the evaluation of the federally-sponsored Anaheim Advanced Traffic Control System Field Operations Test. The primary FOT objective was the implementation and performance evaluation of adaptive traffic signal control technologies including an existing second generation approach, SCOOT, and a 1.5 generation control (1.5GC) approach under development. Also selected for implementation was a video traffic detection system (VTDS).The SCOOT evaluation was defined relative to existing, first...

Ten Strategies for Freeway Congestion Mitigation with Advanced Technologies

Daganzo, Carlos F.
Laval, Jorge
Munoz, Juan Carlos
2002

This report presents ten strategies for improving freeway performance that have become feasible with the advent of new software and hardware technologies for traffic control. Most of the strategies can be applied with advanced implementations of existing hardware. The strategies have in common that they can be rigorously tested. heir measures of performance can be reliably obtained and do not depend on the accuracy of data- hungry, large-scale models.

The Netcell Simulation Package: Technical Description

Cayford, Randall
Lin, Wei-Hua
Daganzo, Carlos F.
1997

This report describes the NETCELL simulation package. NETCELL is a freeway network simulation program based on the cell transmission model which captures the dynamic evolution of multicommodity traffic over a freeway network with three-legged junctions in a way that is consistent with the hydrodynamic theory of highway traffic. NETVIEW is a graphical postprocessor for viewing NETCELL output files. This document discusses implementation of the programs in detail, including the cell representation for a freeway network with three-legged junctions, data and file structures, inputs and outputs...

Methods for Identifying High Collision Concentration Locations for Potential Safety Improvements

Geyer, Judy
Lankina, Elena
Chan, Ching-Yao
Ragland, David
Pham, Trinh
Sharafsaleh, Ashkan
2008

The California Department of Transportation (Caltrans) uses Table C and related documents to identify and to investigate locations within the state highway system where a relatively large number of collisions occur. In earlier years, a task force evaluated the process of generating and using these reports and found that there was much room for improvements. A list of recommendations was made. The efforts undertaken within this project is part of the effort to make the process of safety investigations and improvements more efficient and productive. This report summarizes the work carried...

A Theory Of Traffic Flow In Automated Highway Systems

Broucke, M.
Varaiya, P.
1995

This paper presents a theory for automated traffic flow, based on abstraction of vehicle activities such as entry, exit and cruising, derived from a vehicle's automatic control laws. The theory formulates TMC traffic plans as the specification of the activities and speed of vehicles, and the entry and exit flows for each highway section. The theory permits the study of transient phenomena such as congestion, and TMC feed back traffic rules designed to deal with transients.

Safety and Capacity Analysis of Automated and Manual Highway Systems

Carbaugh, Jason
Godbole, Datta N.
Sengupta, Raja
1999

This paper compares safety of automated and manual highway systems with respect to result- ing rear-end collision frequency and severity. The results show that automated driving is safer than the most alert manual drivers, at similar speeds and capacities. We also present a detailed safety-capacity tradeo study for four di erent Automated Highway System concepts that di er in their information structure and separation policy.

HOT Lane Simulation Tools

Horowitz, Roberto
Kurzhanskiy, Alex A.
Wright, Mathew
2018

This report describes the simulation model and software for freeway corridors with High-Occupancy Vehicle (HOV) and High-Occupancy or Tolled (HOT) lanes, and the model calibration methodology.