PATH

Exploration Of Driver Route Choice With Advanced Traveler Information Using Neural Network Concepts

Yang, Hai
Kitamura, Ryuichi
Jovanis, Paul P.
Vaughn, Kenneth M.
Abdel-aty, Mohammed A.
Reddy, Prasuna Dvg
1993

A model of drivers' route choice behavior under advanced traveler information systems (ATIS) is developed based on data collected from learning experiments using interactive computer simulation. A neural network model is used as a convenient modeling technique in the analysis. Results indicated that most subjects made route choices based mainly on their recent experiences. Results also demonstrated that route choice behavior is related to the personal characteristics as well as the characteristics of the respective routes. Travel experiences had less effect on route choice and the results...

Daily Activity and Multimodal Travel Planner: Phase II Final Report

Kitamura, Ryuichi
Chen, Cynthia
Chen, Jiayu
1999

It is important that our travel be organized in an efficient way. One way to achieve this is to provide travelers with a trip planner that produces efficient travel itineraries for them. It is desired that a trip planner possess the following features in order to be useful: be able to handle multiple destinations, multiple constraints, and multiple modes; and be able to adjust travelers' preferences under different circumstances. These features cannot be found in existing trip planners. The goal is then to develop an "Itinerary Planner" that possesses all of these features. The Itinerary...

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.

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...

Drag Forces Experienced By Two, Full-scale Vehicles At Close Spacing

Hong, Patrick
Marcu, Bogdan
Browand, Fred
Tucker, Aaron
1998

The present study aims to document the drag reduction for a two-vehicle platoon by operating two full-scale Ford Windstar vans in tandem on a desert lakebed. Drag forces are measured with the aid of a special tow bar force measuring system designed and manufactured at USC. The testing procedure consists of a smooth acceleration, followed by a smooth deceleration of the platoon. Data collected during acceleration allows the calculation of the drag force on the trail-vehicle, while data collected during deceleration is used to calculate the drag on the lead vehicle. Results from the full-...

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...

Transient Vehicle Aerodynamics In Four-car Platoons

Chen, A. L.
Savas, Omer
Hedrick, Karl
1997

The vehicles in a platoon will experience transient aerodynamic forces as vehicles leave and join the platoon at various locations. A platoon of scale vehicle models is placed in a wind tunnel and measurements are made of the transient forces and moments as one of the vehicles is moved into and out of the platoon. The results from the wind tunnel experiments will allow the computer vehicle control algorithms to better predict the transient aerodynamics the vehicles in the platoon will encounter during leaving and joining maneuvers. \par Since a lane change (either leaving or joining a...

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

Transit Signal Priority Research Tools

Li, Yuwei
2008

This report addresses Transit Signal Priority (TSP) deployment issues. It reviews National Transportation Communications for ITS Protocol (NTCIP) 1211 Signal Control and Prioritization (SCP) standards, defines five SCP scenarios, and describes how the SCP scenarios can be applied differently based on TSP priority and operating policies. The report provides an overview of a number of TSP systems, including centralized TSP, two discrete TSP systems based on loop detection and Global Positioning System (GPS) technologies, and an Adaptive Transit Signal Priority (ATSP) system. A comparison of...

Unified Lateral Motion Control Of Vehicles For Lane Change Maneuvers In Automated Highway Systems

Chee, Wonshik
Tomizuka, Masayoshi
1997

This report deals with the lateral guidance of vehicles, with focus on lane change maneuvers. Two approaches are presented for lane changes maneuvers. The first is to treat the maneuvers as a tracking control problem. A virtual desired trajectory (VDT) is used a tracking control approach. The second is to use a unified lateral guidance algorithm which consists of the desired yaw rate generator and the yaw rate tracking controller.