Data

Improving Operations Using Advanced Surveillance Metrics and Existing Traffic Detectors

Coifman, Benjamin
Varaiya, Pravin
2002

1 OVERVIEW Because travel time provides information over an extended freeway link, rather than at a single point, it is a key parameter for ATIS applications and it is a powerful tool for ATMS. Under PATH sponsorship, we have already developed a prototype travel time measurement system that utilizes existing dual loop speed traps and "model 170" controllers. This research has advanced the work by improving the vehicle reidentification algorithms (Sections 2 and 3) and applying the travel time measurement system over seven freeway links in real-time (Section 4). This latter work was...

Intelligent Diagnosis Based On Validated And Fused Data For Relilability And Safety Enhancement Of Automated Vehicles In An IVHS

Agogino, Alice
Chao, Susan
Goebel, Kai
Alag, Satnam
Cammon, Bradly
Wang, Jiangxin
1998

Vehicles in an IVHS system rely heavily on information obtained from sensors. So far, most control systems make the implicit assumption that sensor information is always correct. However, in reality, sensor information is always corrupted to some degree by noise which varies with operating conditions, environmental conditions, and other factors. In addition, sensors can fail due to a variety of reasons. To overcome these shortcomings, sensor validation is needed to assess the integrity of the sensor information and adjust or correct as appropriate. In the presence of redundant information...

Incident Management: Process Analysis and Improvement

Hall, Randolph W.
2001

This is the final report for the project Incident Management:Process Analysis and Improvement.The report summarizes findings from three earlier working papers (1998-31,2000-14 and 2000-15)completed under this project, and provides additional analysis on specific scenarios. This study highlights the importance of the following principles: 1)Response units should be adequate in number to handle anticipated demand. 2)Response units should be strategically located to minimize maximum response times. 3)Especially during busy periods,response units should not be dispatched over long distances.It...

Improving Performance of Coordinated Signal Control Systems Using Signal and Loop Data

Li, Meng
Zhang, Liping
Song, Myoung Kyun
Wu, Guoyuan
Zhang, Wei-Bin
Zhang, Lihui
Yin, Yafeng
2010

In this project, a traffic data collection system based-on the iDEN wireless network has been developed, lab tested and preliminarily tested in the field. The objective of the system is to provide a cost-effective and easy-to-maintain system that could still reliably provide traffic data over the wireless link.The project team developed an arterial performance measurement method that is based on the signal infrastructure data collected at PT2 Lab, U.C. Berkeley. The performance of the proposed model is illustrated by using a simulation study. The six-signal simulation network covers both...

Field Investigation of Advanced Vehicle Reidentification Techniques and Detector Technologies - Phase 1

Ritchie, Stephen G.
Park, Seri
Oh, Cheol
Sun, Carlos
2002

This report presents the results of Phase I of a multi-year research effort on "Field Investigation of Advanced Vehicle Reidentification Techniques and Detector Technologies," and extends previous PATH research by the authors on MOU 336 "Section-Related Measures of Traffic System Performance: Prototype Field Implementation." The focus of this research included the following: significant expansion and enhancement of the ILD-based vehicle reidentification system at a major signalized intersection in Irvine, California to address reidentification of turning vehicles in addition to through...

Evaluating Wireless Broadband and System At California Safety Roadside Rest Areas

Finson, Rachel S.
Lidicker, Jeffrey
Phan, Cynthia
Rodier, Caroline
2008

To meet the demand for Internet access by the traveling public, the California Department of Transportation (Caltrans) launched a field operational test of wireless Internet access (WiFi) at two Safety Roadside Rest Areas (SRRAs), Phillip S. Raine and Enoch Christoffersen, along State Route (SR) 99 in July 2007. In this report, researchers evaluate the potential of WiFi at California’s SRRAs in order to make recommendations for future public agency participation in SRRA WiFi partnerships. A number of methods were used to gain insight into the potential of WiFi at SRRAs including (1) expert...

Development of the Advanced Rotary Plow (ARP) for Snow Removal Operations

Tan, Han-Shue
Bu, Fanping
Bougler, Bénédicte
Koo, Shiang-Lung
Nelson, David
Chang, Joanne
Lian, Thang
2006

This final report describes the development and the initial field test of an automated snowblower, focusing on one of the more difficult snow removal operations: blowing snow off the freeway along side a guardrail without touching the guardrail. The objective is to minimize damage to the snowblower, guardrail, and other elements of the infrastructure by deploying highly accurate and robust automated steering. The automatic steering is accomplished by following magnets embedded under the roadway. The development process includes transforming this real-world automated highway winter...

Micro-simulation Modeling Approach to Applications of On-line Simulation and Data Fusion

Chu, Lianyu
Recker, Will
2004

This report summarizes research work conducted under TO4143 at the California PATH ATMS Center at the University of California, Irvine. This project has two tasks: Functionality enhancements of the PARAMICS simulation model through API programming for the on-line simulation application; On-line data fusion algorithm for a better section travel time estimation based on point detector data and probe vehicle data. In order to conduct these two tasks, we complete the following two related studies, which are the basis of the two tasks of this project: Development of the capability-enhanced...

Effectiveness of California’s High Occupancy Vehicle (HOV) System

Varaiya, Pravin
2007

This is the most extensive empirical evaluation of the effectiveness of California’s HOV system based on data collected from traffic sensors. The evaluation leads to four major conclusions. (1) Since it operates as a single lane freeway, an HOV lane suffers a 20 % capacity loss compared with multi-lane freeways. (2) HOV lanes are either under-utilized or suffer degraded operations. (3) HOV lanes do not measurably increase car-pooling. (4) HOV lanes do not reduce overall congestion in a reasonably well-managed system.

Area under the curve as an alternative to latent growth curve modeling when assessing the effects of predictor variables on repeated measures of a continuous dependent variable

Rodriguez, Daniel
2023
Researchers conducting longitudinal data analysis in psychology and the behavioral sciences have several statistical methods to choose from, most of which either require specialized software to conduct or advanced knowledge of statistical methods to inform the selection of the correct model options (e.g., correlation structure). One simple alternative to conventional longitudinal data analysis methods is to calculate the area under the curve (AUC) from repeated measures and then use this new variable in one’s model. The present study assessed the relative efficacy of two AUC measures: the AUC...