PATH

A Combined Quantitative and Qualitative Approach to Planning for Improved Intermodal Connectivity at California Airports

Lu, Xiao-Yun
Gosling, Geoffrey D.
Ceder, Avi
Tung, Steven
Tso, Kristin
Shladover, Steven
Xiong, Jing
Yoon, Sangwon
2009

This report has been prepared as the final deliverable for a research project developing a combined quantitative and qualitative approach to planning for improved intermodal connectivity at California airports. The quantitative approach involves the development of an Intermodal Airport Ground Access Planning Tool (IAPT) that combines transportation system performance measurement, an air passenger mode choice model, and a model of transportation provider behavior, and is designed to interface with a traffic network analysis model. The qualitative approach is used to enhance the quantitative...

Determining the Effectiveness of HOV Lanes

May, Adolf D.
Leiman, Lannon
Billheimer, John
2007

This document is the final report for the two-year PATH Project “Determining the Effectiveness of HOV Lanes”. It has been supported by the California Department of Transportation (Caltrans). The primary objectives of this project have been to evaluate freeways having on-freeway HOV lanes in terms of vehicle-travel, person-travel, occupancy distribution, shape and duration of the peak period, congestion patterns, and air quality both in the HOV lane and the adjacent mixed-flow lanes.Based on a comprehensive literature review an extensive list of reference was developed, along with summaries...

Cartesius and CTNET Integration and Field Operational Test

Rindt, Craig R.
McNally, Michael G.
2009

This report describes the results of PATH Task Order 5324—the first year of a multi-year project to integrate the Cartesius incident management system with Cal-trans CTNET traffic signal management system. The results of this research are a set of software requirements for reimplementing the Cartesius to interoperate with CTNET. An analysis of the existing Cartesius prototype explains how the need to focus the system on deployment and technical shortcomings of the existing system justifies a reimplementation of the software. From here, we describe the problem to be solved by the new...

Analysis Toward Mitigation of Congestion and Conflicts at Light Rail Grade Crossings and Intersections

Li, Meng
Wu, Guoyuan
Johnston, Scott
Zhang, Wei-Bin
2009

Although many different railroad grade crossing control products are available, the most challenging limitation to traditional grade crossing systems is their inability to deliver consistent warning times in response to varying train speeds and station stops (particularly nearside stops). As a result, rail-roadway crossings often generate conflicts and congestion for motorist traffic and sometimes delay trains.By conducting system level analysis, this project will investigate the interactions and conflicts between urban/suburban rail and cross traffic. The information that is obtained will...

Consumer Demand For Automated Private Travel: Extrapolations From Vanpool User Experiences

Bonanno, Nirupa
Sperling, Daniel
Kurani, Kenneth S.
1993

The purpose of this study is to investigate the reasons for an individual' s decision to ride rather than drive, and to draw any appropriate extensions to a future marketplace where automated vehicles may be an available mode choice. In the study, a focus group of existing vanpoolers is presented with the choice of driving alone or commuting with others after they had joined the vanpool. From the vanpoolers' stated choices, it is inferred whether a value may exist to future users of automated vehicles when they choose to travel in the automated mode, as opposed to driving themselves.

Sensor-Friendly Freeways: Investigation of Progressive Roadway Changes to Facilitate Deployment of AHS

Misener, James A.
Griffiths, Paul
Johnson, Lee
Segal, Andy
2001

Intelligent "driver assistance" systems which utilize in-vehicle forward-looking sensors can be supplemented by vehicle-vehicle and vehicle-highway cooperative elements to comprise a "sensor-friendly" highway environment that would enhance the operational efficiency, and ultimately, the safety benefits of these systems. In our research, we have identified the current limitations of autonomous sensing systems in target/background discrimination with cluttered highways. Based upon this, and by limiting ourselves to "sensed" (and not wireless) systems, we have conceived relatively inexpensive...

Real-time Density Estimation on Freeway with Loop Detector and Probe Data

Qiu, Tony Z.
Lu, Xiao-Yun
Chow, Andy H. F.
Shladover, Steven
2009

Density, speed and flow are the three critical parameters for traffic analysis. Traffic management and control with high performance require accurate estimation/prediction of distance mean speed and density for large spatial and temporal coverage. Speed, including time mean speed and distance mean speed, and flow estimation are relatively easy to be measured and estimated in the practical site, but accurate density estimation is very difficult. Inductive loop detector systems have been widely deployed, it makes better sense to fully adopt available infrastructure to achieve required...

Models, Simulation, And Performance Of Fully Automated Highways

Varaiya, Pravin
1994

The research findings presented in this report deal with the modeling, simulation and performance evaluation of fully automated highway systems ( AHS). The report begins with a brief reconstruction of the history of the AHS concept, and a particular AHS proposal that has been intensely studied in PATH. The next section summarizes the principal findings of AHS performance. This is followed by an overview of the simulation program SmartPath. An outline of the current work on SmartPath and plans for the immediate future are given. This section also proposes an object oriented distributed...

Evaluation of Wet Weather Accident Causation Criteria

Oh, Soon Mi, MS
Ragland, David R., PhD
Chan, Ching-Yao, PhD
2010

This report documents findings from analysis of traffic collision data from sites that display high collision rates only under wet pavement conditions. These sites were selected using Caltrans safety engineers’ field reports, Wet Table C “investigation required” locations, and a new approach called Continuous Risk Profile (CRP).The geometric features at the sites were studied via field visits and review of as-built plans. Rapid spatial changes (i.e., vertical and horizontal curve in short distance), narrower lane width, lack of median, and wider total freeway width were some of the notable...

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...