Travel Behavior

Medium Access Control Protocol Design for Vehicle-Vehicle Safety Messages

Xu, Qing
Mak, Tony
Ko, Jeff
Sengupta, Raja
2005

We propose a Medium Access Control (MAC) protocol design for a vehicle to send safety messages to other vehicles. We develop a QoS model for safety messages consistent with the active safety systems literature. Each message has a range and useful lifetime. The QoS target is to have each message be received with high probability within its specified lifetime by each vehicle within its specified range. The protocol design is based on rapidly re-broadcasting each message multiple times within its lifetime in combination with the 802.11 DCF. This makes the design compatible with the emerging...

Evaluation of Incorporating Hybrid Vehicle Use of HOV Lanes

Brownstone, David
Chu, Lianyu
Golob, Tom
Nesamani, K.S.
Recker, Will
2008

This report presents a method to investigate the operational and environmental effects of the policy of allowing qualified single-occupancy hybrid vehicles to use dedicated High-Occupancy Vehicle (HOV)/carpool lanes in California.. The method combines the traditional planning method with microscopic simulation modeling. The planning method is used for demand estimation and analysis and the microscopic traffic simulation modeling method is used for accurate measures of the system. The study employs a microscopic traffic simulation model that is capable of evaluating the HOV/hybrid system...

Evaluating System ATMIS Technologies Via Rapid Estimation Of Network Flows: Final Report

Moore, II, James E.
Kim, Geunyoung
Cho, Seongdil
Hu, Hsi-hwa
Xu, Rong
1997

This report studies how flows in large scale transportation networks can be subjected to rapid estimation. It describes an efficient transportation network analysis (TNA) procedure that provides the system-wide changes of network flows under numerous scenario earthquakes. The first objective of this research is to provide reliable estimates of network flows with respect to changes in transportation networks, and to incorporate these changes to the decision-making procedures used by the California Department of Transportation (Caltrans) in making bridge retrofit decisions. The second...

Considering Risk-Taking Behavior in Travel Time Reliability

Recker, Will
Chung, Younshik
Park, Jiyoung
Wang, Lesley
Chen, Anthony
Ji, Zhaowang
Liu, Henry
Horrocks, Matthew
Oh, Jun-Seok
2005

Travel time variability is increasingly being recognized as a major factor influencing travel decisions and, consequently, as an important performance measure in transportation management. In this research project, we examine a number of questions related to travel time variability: How should travel time variability be quantified at both the section level as well as at the route level?; How do travelers value travel time and its reliability?; How much does the travel time reliability contribute to travelers' route choices?; How much variation is there in travelers' preferences regarding...

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...

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...

Validation of Daganzo's Behavioral Theory of Multi-Lane Traffic Flow: Final Report

Banks, James H.
Amin, Mohammad R.
Cassidy, Michael
Chung, Koohong
2003

A study was conducted to verify C. F. Daganzo's behavioral theory of multi-lane traffic flow (1, 2). This study was conducted by teams from San Diego State University and the University of California at Berkeley who worked independently on a series of case studies to test predictions derived from the theory. The results of the study suggest that some of the phenomena predicted by Daganzo do occur, but not at all locations, and that the underlying behavioral assumptions are oversimplified. Specifically, the types of flow- density (or flow-occupancy) relationship assumed by Daganzo were...

Expedited Crash Investigation - With Use of Technologies for Documentation and Processing

Chan, Ching-Yao
Lian, Thang
Ko, Jeff
2007

The mobility and efficiency of California highways are impeded by the recurrent and non-recurrent congestion on a daily basis. Roadway incidents, especially collisions, often result in traffic congestion and travel delays. This project is initiated to explore the use of technologies that will potentially bring direct and immediate benefits to the law enforcement officers and other personnel who are involved in the handling of collision sites and subsequent investigations. The work carried out in this project includes three major components: (1) The experimentation of integrated vehicular...

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...