PATH

Fuzzy Traffic Density Homogenizer For Automated Highway Systems

Chien, C. C.
Ioannou, P.
Chu, C.K.
1995

In this paper, a fuzzy traffic density homogenizer is proposed to alleviate or avoid congestion by smoothing the traffic density distribution profile over freeway lanes. The proposed fuzzy homogenizer consists of two parts: the fuzzy mean speed controller and the fuzzy on- ramp controller. Simulation results are used to demonstrate that the proposed controllers can eliminate traffic flow instabilities leading to smooth traffic flows.

Vehicle/Driver Monitoring for Enhanced Safety of Transit Buses

Shi, Mingyu
Tomizuka, Masayoshi
2007

This report documents the findings of the study “Vehicle/Driver Monitoring for Enhanced Safety of Transit Buses” conducted as part of the PATH project TO5400. The goal of study TO5400 is todesign and implementation of a reliable vehicle/driver monitoring system with aim to enhance driving safety of transit buses.The main objectives of the project are: (1) to identify a simply model that best describes the driving patterns of human drivers, and (2) to develop an algorithm which can generate warning messages when there is a provision of danger.In this study, it is assumed that the driver...

Evaluation Of Radio Links And Networks

Linnartz, Jean-Paul M.G.
Diesta, Rolando F.
1996

This study evaluates the performance of radio links and networks to support communication with Automatic Vehicle Control Systems (AVCS). It addresses both vehicle-to-vehicle communication and roadside-to-vehicle communication. The report contributes to the modelling of short range vehicle-to-vehicle channels, not only in terms of documenting measured results and channel parameters, but also in extending existing models to cover antenna mobility at both receiver and transmitter simultaneously. These models are applied to compute the Bit Error Rate performance over radio links. The network...

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 away 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...

Automated Truck Platoon Control

Lu, Xiao-Yun
Shladover, Steven E.
2011

This report shows a successful application of 5.9 GHz DSRC with 100 ms update intervals to coordinate the automatic longitudinal control of a platoon of three Class 8 tractor-trailer trucks. The trucks were tested not only in constant-speed cruising conditions, but also through acceleration and deceleration profiles, up and down grades, and in platoon join and split maneuvers using the DSRC coordination. These tests showed acceptable vehicle following accuracy, ride quality and platoon stability. The gaps between the trucks were varied between 10 m and 4 m to evaluate the effects of...

Bay Area ATIS Testbed Plan

Khattak, Asad
Al-Deek, Haitham
Yim, Youngbin
Hall, Randolf
1992

Several factors have motivated the development of Intelligent Vehicle Highway Systems (IVHS); among them are growing traffic congestion, concern for environmental degradation, the need to improve safety, and the desire to best utilize existing transportation infrastructure. Within the framework of M-IS, Advanced Traveler Information Systems (ATIS) will provide historical, real-time and predictive information to support travel decisions. ATIS offers significant benefits interms of improving the travel experience of individuals and enhancing system performance. In the long-term, ATIS may...

High Collision Concentration Location: Table C Evaluation and Recommendations

Ragland, David
Chan, Ching-Yao
2008

This report describes the research work that was conducted to improve the effectiveness and consistency of methods for identifying High-Concentration Collision Locations (HHCL) within the California State Highway System that have collision frequencies significantly greater than expected when compared to other locations. The accuracy and reliability of HCCL reports are critical as the outcome of the screening process is the basis for follow-up field investigation as well as potential safety improvements.During the course of the project, the research team from the Traffic Safety Center (TSC...

Commuters’ Normal and Shift Decisions in Unexpected Congestion: En Route Responses to Advanced Traveler Information Systems Volume 2

Polydoropoulou, Amalia
Ben-Akiva, Moshe
Khattak, Asad
Lauprete, Geoffrey
1996

Advanced Traveler Information Systems (ATIS) are being developed to provide travelers with real-time information about traffic conditions. To evaluate the benefits of ATIS products and services, questions concerning potential market, usage, and travel response must be addressed. This paper focuses on en-route travel response to ATIS. The main objective is to explore how travelers deal with unexpected congestion and how they might respond to qualitative, quantitative, prescriptive and predictive information. Data on travelers’ route switching decisions are obtained through a survey of...

New Data and Methods for Estimating Regional Truck Movements

Dion, Francois, PhD
Yang, Mingyuan
Patire, Anthony, PhD
2023

This report describes how current methods of estimating truck traffic volumes from existing fixed roadway sensors could be improved by using tracking data collected from commercial truck fleets and other connected technology sources (e.g., onboard GPS-enabled navigation systems and smartphones supplied by third-party vendors). Using Caltrans District 1 in Northern California as an example, the study first reviews existing fixed-location data collection capabilities and highlights gaps in the ability to monitor truck movements. It then reviews emerging data sources and analyzes the...

Calibration of VISSIM for a Congested Freeway

Gomes, Gabriel
May, Adolf
Horowitz, Roberto
2004

A procedure for constructing and calibrating a detailed model of a freeway using VISSIM is presented and applied to a 15-mile stretch of I-210 West in Pasadena, California. This test site provides several challenges for microscopic modeling: an HOV lane with an intermittent barrier, a heavy freeway connector, 20 metered onramps with and without HOV bypass lanes, and three interacting bottlenecks. Field data used as input to the model was compiled from two separate sources: loop-detectors on the onramps and mainline (PeMS), and a manual survey of onramps and offramps. Gaps in both sources...