Roads/Highways

Integrated Ramp Metering Design and Evaluation Platform with Paramics

Chu, Lianyu
Recker, Will
Yu, Guizhen
2009

Ramp metering has been recognized as an effective freeway management strategy to either avoid or ameliorate freeway traffic congestion by limiting access to the freeway. California has applied ramp metering widely in major metropolitan areas. Currently, California has three major ramp metering systems: San Diego Ramp Metering System (SDRMS), Semi-Actuated Traffic Management System (SATMS), and Traffic Operations System (TOS). Although the ramp metering algorithms that underlay these systems are based on relatively simple theoretical concepts, these real-world ramp metering systems are...

Automated Highway System Field Operational Tests For The State Of California: Potential Sites, Configurations And Characteristics

Hall, Randolph W.
Thakker, Viral
Horan, Thomas A.
Glazer, Jesse
Hoene, Chris
1997

This report describes possible objectives for a Field Operational Test (FOT), to be conducted following the completion of the National Automated Highway System Consortium (NAHSC) mission in 2002. At that time, it is anticipated that there will be one or more FOTs in which ordinary drivers will use automated vehicles on a real roadway, under test conditions. The report also identifies potential test sites in California, and evaluates the merits of these sites for conducting different types of tests.

Simple Results on Communication With Neighbors

Puri, Anuj
Varaiya, Pravin
1999

Normal Communication Networks require the Sender to specify the address of the Receiver before communication can take place. In problems that a rise in an Automated Vehicle Highway System, the Sender can identify the Receiver by its physical location only (i.e. a car wanting to communicate with the car immediately in front of it). Normal Communication Procedures that use the Receiver's Address to establish communication must be preceded by an Address Finding Protocol. An Address Finding Protocol which uses the Absoulate Location of vehicles has been proposed in [2] and is reviewed in...

Development and Testing of Field-Deployable Real-Time Laser-Based Non-Intrusive Detection System for Measurement of True Travel Time on the Highway

Cheng, Harry H.
Shaw, Ben
Palen, Joe
Hu, Xudong
Lin, Bin
Larson, Jonathan E.
Van Katwyk, Kirk
2001

We have developed a field prototype of a laser-based non-intrusive detection system for real-time measurement of delineations of moving vehicles for highway testing, based on our previous research on the laboratory prototype of the system. The primary goal of this project is to develop a roadway detection system that can be used to gather reliable travel time data non-intrusively. The system uses a laser line that is projected onto the ground as a probe. The reflected light is collected and focused into a photodiode array by an optical system. Vehicle presence is detected based on the...

Integrated Maneuvering Control Design And Experiments: Report For Phase III

Hedrick, J. K.
Yoshioka, T.
Chen, Y. H.
Connolly, T.
Shen, L. R.
1997

In this report, a Cooperative Intelligent Cruise Control (CICC) System is proposed to increase highway capacity and provide safety and comfort to drivers. The method requires an automatic throttle and brake control and simple infrastructure-vehicle communication. The system is designed to let a vehicle operate under a conventional cruise control system as well as a distancing control system. The performance of the CICC is evaluated through simulations with a non-linear vehicle model.

Automated Travel Time Measurement Using Vehicle Lengths from Loop Detector Speed Traps

Coifman, Benjamin
Cassidy, Michael
2000

This report presents a vehicle reidentification algorithm for consecutive detector stations on a freeway, whereby a vehicle measurement made at a downstream detector station is matched with the vehicle's corresponding measurement at an upstream station. The algorithm should improve freeway surveillance by measuring the actual vehicle travel times; these are simply the differences in the times that each (matched) vehicle arrives to the upstream and downstream stations. Thus, it will be possible to quantify conditions between widely spaced detector stations rather than assuming that the...

Capacity Of Automated Highway Systems: Effect Of Platooning And Barriers

Tsao, H. S. Jacob
Hall, Randolf
Hongola, Bruce
1994

In this paper, the authors study the capacity of key Automated Highway Systems (AHS) operating scenarios. The effect of the lane-flow rule, platooning or free-agent, as well as the lane barriers, on AHS capacity are studied. Special attention is paid to the interaction between the lane-flow rule and the lane change requirement. The paper consists of two major components, analytical models and AHS simulation. After a brief introduction of AHS operating strategies, analytical models are developed for general AHS. For simulation, the authors focus on a segregated AHS that has one automated...

Lateral Control Of Tractor-semitrailer Vehicles In Automated Highway Systems

Chen, Chien
Tomizuka, Masayoshi
1996

In this paper, linear quadratic optimal control with and without frequency shaping is utilized to design a steering controller for tractor- semitrailer vehicles in Automated Highway Systems (AHS). To enhance driving safety, the authors propose to use independent braking forces in the trailer as another control input. The combined steering and braking controller is designed by utilizing Input/Output linearization and backstepping design techniques.

Anonymous Vehicle Tracking for Real-Time Freeway and Arterial Street Performance Measurement

Ritchie, Stephen G.
Park, Seri
Oh, Cheol
Jeng, Shin-Ting (Cindy)
Tok, Andre
2005

This research involved an important extension of existing field-implemented and tested PATH research by the authors on individual vehicle reidentification, to develop methods for assessing freeway and arterial (and transit) system performance for the Caltrans PeMS (Performance Measurement System). PeMS has been adopted by Caltrans as the standard tool for assessing freeway system performance, but lacks capabilities for assessing arterial and transit system performance, and strategies that combine freeways, arterials and/or transit and commercial vehicle fleets. It was shown that the...

Optimal Emergency Maneuvers Of Automated Vehicles

Shiller, Zvi
Sundar, Satish
1996

This work addresses two issues related to emergency maneuvers of autonomous vehicles. The first concerns the time-optimal speeds along specified path, which can be used to design emergency maneuvers. The second concerns the computation of optimal lane-change maneuvers for on- line collision avoidance. Although considering only a simple planar vehicle model, this work provides insights into the dynamic behavior of ground vehicles