PATH

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...

Geographical Routing Using Partial Information for Wireless Ad Hoc Networks

Jain, Rahul
Puri, Anuj
Sengupta, Raja
2001

In this paper, we present an algorithm for routing in wireless ad hoc networks using information about geographical location of the nodes. We assume each node knows its geographical position and the position of the node to which it wants to send a packet. Initially, the nodes only know their neighbors but over time they discover other nodes in the network. The routing table at a node S is a list ((pi, Si)) where pi is a geographical position and Si is a neighbor of node 5’. When node S receives a packet for a node D at position pos(D), it finds the pi in its routing table which is closest...

Stated And Reported Diversion To Public Transportation In Response To Congestion: Implications On The Benefits Of Multimodal ATIS

Khattak, Asad
Le Colletter, Emmanuel
1994

The objective of this study is to evaluate the potential benefits of a multimodal Advanced Traveler Information System (ATIS). The propensity of auto commuters to switch to public transportation in response to unexpected traffic congestion is investigated using a detailed survey undertaken in the Golden Gate Bridge corridor in 1993. A stated preference analysis tied to the situation for which the commuting behavior was reported is used to estimate the propensity of travelers to divert to transit under a multimodal ATIS.

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...

Field Investigation of Advanced Vehicle Reidentification Techniques and Detector Technologies - Phase 2

Ritchie, Steven
Park, Seri
Oh, Cheol
Jeng, Shin-Ting
Tok, Andre
2005

This report presents the results of Phase 2 of a multi-year research effort on "Field Investigation of Advanced Vehicle Reidentification Techniques and Detector Technologies." Phase I of this research was conducted under PATH MOU 3008. Phases I and II of this research extended previous PATH research by the authors on MOU 336 "Section-Related Measures of Traffic System Performance: Prototype Field Implementation." Phase II of this research continued development, field investigation and assessment of the latest technologies available for traffic detection and surveillance, for collecting...

Fuzzy Throttle And Brake Control For Platoons Of Smart Cars

Kim, H.
Dickerson, J.
Kosko, B.
1995

This study demonstrates the use of an additive fuzzy system to control the velocity and gap of cars in a single lane two-car platoon. A throttle- only controller and a combined throttle and braker controller were tested. Simulation results show that follower cars with a combined brake/ throttle controller can maintain a constant gap when the platoon goes down hills and slows. An adaptive throttle controller uses a neural system to learn the fuzzy rules for different vehicle types.

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

Spacing And Capacity Evaluations For Different Ahs Concepts

Kanaris, Alexander
Ioannou, Petros
Ho, Fu-sheng
1996

In this study, the authors consider a family of six Automated Highway Systems (AHS) operational concepts. For each concept, the minimum inter- vehicle spacing that could be used for collision-free vehicle following, under different road conditions, is calculated. For architectures involving platoons, the authors also use the alternative constraint of bounded energy collisions to calculate the spacing that can be applied if collisions at a limited relative velocity were allowed. In every case, the minimum spacing in turn, is used to calculate the maximum possible capacity that could be...

Development and Field Testing of Laser Photodiode Array-Based Vehicle Detection Systems

Cheng, Harry H.
Shaw, Ben
Palen, Joe
Wang, Zhaoqing
Feng, Ping
Nestinger, Stephen
Chen, Bo
2004

Over the past year we have researched the development of a network-based real-time laser-based nonintrusive field-deployable detection for the delineation of moving vehicles. 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. A powerful Rabbit 3200, instead of multi-microchips, is used to control digitally controlled potentiometers (DCP), which adjust the gain of the sensors' signals. Utilizing digitally controlled potentiometers allow for quick and easy adjustment on the highway with only the need...

Developing Calibration Tools for Microscopic Traffic Simulation Final Report Part 1: Overview Methods and Guidelines on Project Scoping and Data Collection

Zhang, Michael
Ma, Jingtao
1998

The purpose of MOU-233 is to evaluate and test a low cost, short range radar sensor developed by Amerigon corporation through a subcontract with the University of Southern California. The radar is designed to be used as a ranging sensor for automatic vehicle following applications. It is intended to be mounted in the front of the vehicle and provide measurements of the distance between the front of the vehicle and the rear of any vehicle or object ahead within a maximum distance of 17 feet. The output of the radar as supplied by Amerigon, is a 32-bit binary code, using one bit to represent...