Development of a Path Flow Estimator for Deriving Steady-state and Time-dependent Origin-destination Trip Tables


Book Description

The origin-destination (O-D) trip table is a key input required for traffic assignment and simulation models utilized to analyze a wide variety of transportation applications. The main goal of this research is to develop an economical and quick method for estimating O-D trip tables from traffic counts. Path flow estimator (PFE), originally developed by Bell and Shield (1995), has been further developed to improve the reliability and efficiency of O-D trip table estimates. The research reported herein includes only the development of the steady-state O-D estimator. In this study, the original PFE model was carefully examined in several aspects to gain more insight for further improvements. Currently, the PFE has been successfully applied to estimate the steady-state O-D trip tables for the Irvine Testbed network in Orange County, California as well as some other real networks. The primary results demonstrate that PFE has the capability to correctly estimate the total and individual O-D demands when proper information is provided. They also indicate that the number and locations of traffic counts significantly influence the quality of O-D estimates as each observation contributes different amount and quality of information. The most difficult task observed thus far is the estimation of spatial pattern of O-D demands even when traffic counts were collected on all network links. These issues and the development of time-dependent PFE will be investigated in the second phase under Task Order 5502







Advances in Automation and Robotics, Vol.1


Book Description

The international conference on Automation and Robotics-ICAR2011 is held during December 12-13, 2011 in Dubai, UAE. The proceedings of ICAR2011 have been published by Springer Lecture Notes in Electrical Engineering, which include 163 excellent papers selected from more than 400 submitted papers. The conference is intended to bring together the researchers and engineers/technologists working in different aspects of intelligent control systems and optimization, robotics and automation, signal processing, sensors, systems modeling and control, industrial engineering, production and management. This part of proceedings includes 81 papers contributed by many researchers in relevant topic areas covered at ICAR2011 from various countries such as France, Japan, USA, Korea and China etc. Many papers introduced their advanced research work recently; some of them gave a new solution to problems in the field, with powerful evidence and detail demonstration. Others stated the application of their designed and realized systems. The session topic of this proceeding is intelligent control and robotics and automation, which includes papers about Distributed Control Systems, Intelligent Fault Detection and Identification, Machine Learning in Control, Neural Networks based Control Systems, Fuzzy Control, Genetic Algorithms, Robot Design, Human-robots Interfaces, Network Robotics, and Autonomous Systems, Industrial Networks and Automation, Modeling, Simulation and Architectures, Vision, Recognition and Reconstruction, Virtual Reality, Image Processing, and so on. All of papers here involved the authors’ numerous time and energy, will be proved valuable in their research field. Sincere thanks to the committee and all the authors, moreover anonymous reviewers from many fields and organizations. That is a power for all of us to go on research work for the world.




International Conference on Transportation Engineering 2007


Book Description

This collection contains 690 papers presented at the First International Conference on Transportation Engineering, held in Chengdu, China, July 22-24, 2007.




Biennial Report


Book Description
















Estimation of an Origin-destination Trip Table Based on Observed Link Volumes and Turning Movements: Technical report


Book Description

The LINKOD modeling system estimates a trip table based on observed link volumes and turning movements. This trip table can be used as an input to traffic assignment and/or simulation models. LINKOD is designed for small area analysis where all link volumes are known. The system is driven by the models: SMALD, a trip distibution model for small areas, and ODLINK, an adaptable trip table assignment model. SMALD estimates a trip table (the Target table) based on trip rates at sources and sinks, and the network's service level. The ODLINK model corrects an input (Target) trip table, so it best replicates the observed flows, when assigned using equilibrium assignment. The models are driven by the LINKOD software package. The package includes several computer programs which perform input data editing and extensive summaries of the results.