Roads/Highways

Development And Experimental Evaluation Of Autonomous Vehicles For Roadway/vehicle Cooperative Driving

Ioannou, Petros
1998

Automatic vehicle following is an important feature of a fully or partially automated highway system (AHS). The on-board vehicle control system should be able to accept and process inputs from the driver, the infrastructure and other vehicles, perform diag- nostics and provide the appropriate commands to actuators so that the resulting motion of the vehicle is safe and compatible with the AHS objectives. The purpose of this paper is to design and test a vehicle control system in order to achieve full vehicle automation in the longitudinal direction for several modes of operation, where the...

A 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
Wang, Zhaoqing
Chen, Bo
2002

In this research project we are developing a roadway detection system that can directly determineO/D data non-intrusively without violating the public's privacy (as in license plate recognitionsystems). While we have previously developed a real-time laser-based non-intrusive detectionsystem for measurement of true travel time on the highway, we improved the system further. Afeed-back loop, using microchip control, was introduced into the system. This makes the systemeasy to use. The mechanical components were also improved to increase the precision of thesystem. Software to display the...

The I-880 Field Experiment: Effectiveness Of Incident Detection Using Cellular Phones

Skabardonis, Alexander
Chira-chavala, Ted
Rydzewski, Daniel
1996

This report describes the evaluation of the effectiveness and adequacy of cellular phones for incident detection as an alternative to infrastructure-based surveillance systems. The analysis was part of the I-880 field experiment using the California Highway Patrol's (CHP) Computer Aided Dispatch (CAD) incident database. Cellular phones have the highest detection rate among the examined detection sources. Results from the study, however, indicate that incidents reported by cellular phones show greater incident durations than similar incidents reported by the CHP or the Freeway Service...

Field Operational Test of Tools for Facilitating Smart Travel Choices Through Real-Time Information

Zhou, Kun
Wang, Yanqiao
Li, Jingquan
Wachs, Marty
Walker, Joan
Meng, Huadong
Friedman, Jason
Zhang, Wei-Bin
2018

This report documents an effort to assess whetherintegrated multimodal real-time traveler information can encouragetravelers to consider transit as a more viable choice. Under the sponsorship of the California Department of Transportationand in partnership with the Los Angeles Metropolitan Transportation Authority,California PATH developed and field tested Trip2go --a suite of web-based and mobile-phone-based applications incorporating real-time transit and highway condition information. Both objective and surveys were collected to support statistical and modeling analyses to evaluate the...

Finding and Analyzing True Effect of Non-recurrent Congestion on Mobility and Safety

Varaiya, Pravin
2007

This report summarizes empirical research about the causes and impact of non-recurrent congestion. A method is presented to divide the total congestion delay in a freeway section into six components: the delay caused by incidents, special events, lane closures, and adverse weather; the potential reduction in delay at bottlenecks that ideal ramp metering can achieve; and the remaining delay, due mainly to excess demand. The method can be applied to any site with minimum calibration, but it requires data about traffic volume and speed; the time and location of incidents, special events and...

Using Cooperative Adaptive Cruise Control (CACC) to Form High-Performance Vehicle Streams

Shladover, Steven E
Nowakowski, Christopher
Lu, Xiao-Yun
Hoogendoorn, Raymond
2014

This research identifies the operational concepts for managing cooperative adaptive cruise control (CACC) vehicle maneuvering and traffic flows. This includes approaches for grouping the CACC vehicles, ranging from ad-hoc to centrally coordinated strategies, and the incentives that could be used to facilitate the vehicle clustering, both operational and financial. These are particularly important at low market penetrations, when the CACC vehicles are likely to be widely separated. The dissolution of CACC strings is also discussed, since this needs to be done carefully to avoid adverse...

Lane Assist Systems for Bus Rapid Transit, Volume III: Interface Requirements

Bu, Fanping
Zhang, Wei-Bin
Dickey, Susan
Shladover, Steven E.
Tan, Han-Shue
2007

Vehicle Assist and Automation (VAA) systems enable lane assist, precision docking and longitudinal control of transit vehicles. They offer the opportunities of providing high quality transit service within reduced lane widths. Transit vehicles in North America are mostly manufactured based on individual transit agencies’ customized requirements. The interfaces between VAA components and the mechanical, electrical and electronic systems on the existing transit vehicle, if not defined properly, can be an impediment to large scale deployment of VAA technologies. This report summarizes a...

Optimal Preview Control For Vehicle Lateral Guidance

Peng, Huei
Tomizuka, Masayoshi
1991

This report introduces an optimal preview control algorithm which utilizes preview information pertaining to road curvature as well as superelevation angle for vehicle lateral control purposes. The optimal control law consists of both feedback control action and feedforward preview control action. The feedforward preview control action significantly improves tracking performance while maintaining a small closed loop bandwidth so ride quality is not impaired. Frequency domain analyses and numerical simulation results show improvements obtained in both frequency domain and time domain

Opportunities And Constraints For Advanced Highway Technologies: A Speculative Analysis

Deakin, Elizabeth
1989

Might the performance of transportation systems be significantly improved through greater application of emerging technologies? Recent advances in computers, materials, communications, control systems, information systems, and many other areas raise intriguing possibilities.

Potential Benefits Of In-vehicle Information Systems In A Real Life Freeway Corridor Under Recurring And Incident-induced Congestion

Al-deek, Haitham
1988

Optimal use of existing transportation facilities has become a major priority in congested urban areas. Providing real-time in-vehicle traffic information to drivers is one possibility of achieving this goal. This report documents an initial attempt to ascertain the potential benefits of a real-time in-vehicle traffic information system under recurring and non-recurring congestion conditions.