Roads/Highways

Cooperative Adaptive Cruise Control: Testing Drivers’ Choices of Following Distances

Nowakowski, Christopher
Shladover, Steven E.
Cody, Delphine
Bu, Fanping
O'Connell, Jessica
Spring, John
Dickey, Susan
Nelson, David
2011

A Cooperative Adaptive Cruise Control (CACC) system has been developed by adding a wireless vehicle-vehicle communication system and new control logic to an existing commercially available adaptive cruise control (ACC) system. The CACC is intended to enhance the vehicle-following capabilities of ACC so that drivers will be comfortable using it at shorter vehicle-following gaps than ACC. This can offer a significant opportunity to increase traffic flow density and efficiency without compromising safety or expanding roadway infrastructure.This report describes the design and implementation...

Mixed Manual/Semi-Automated Traffic: A Macroscopic Analysis

Bose, Arnab
Ioannou, Petros
2001

The use of advanced technologies and intelligence in vehicles and infrastructure could make the current highway transportation system much more efficient. Semi-automated vehicles with the capability of automatically following a vehicle in front as long as it is in the same lane and in the vicinity of the forward looking ranging sensor are expected to be deployed in the near future. Their penetration into the current manual traffic will give rise to mixed manual/semi-automated traffic. In this paper, we analyze the fundamental flow-density curve for mixed traffic using flow-density curves...

Congestion-Responsive On-Ramp Metering: Recommendations toward a Statewide Policy

Lu, Xiao-Yun
Amini, Zahra
Mauch, Michael
Skabardonis, Alexander
2019

The objective of this project was to develop recommendations toward a statewide policy of congestion responsive freeway ramp metering (CRRM) operation. The research has been performed in the following approaches: First an empirical “before” and “after” freeway corridor performance evaluation was performed on a selected set of California’s freeway corridors that had implemented congestion responsive ramp metering. Next, other important policy and operational factors that impact the effectiveness of extended hours ramp metering were evaluated: traffic detector health and data quality and...

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...