Title page for ETD etd-020599-151231

Type of Document Master's Thesis
Author Paramahamsan, Harinarayan
Author's Email Address hparamah@vt.edu
URN etd-020599-151231
Title Fundamental properties of Synthetic O-D Generation Formulations and Solutions
Degree Master of Science
Department Civil Engineering
Advisory Committee
Advisor Name Title
Van Aerde, Michael W. Committee Chair
Rakha, Hesham Ahmed Committee Member
Trani, Antonio A. Committee Member
  • Maximum Likelihood
  • Maximum Entropy
  • O-D
  • Synthetic
Date of Defense 1999-01-22
Availability unrestricted
Fundamental properties of Synthetic O-D Generation Formulations and Solutions


Origin-Destination (O-D) matrices are required in order to model traffic routing behavior in networks. Direct techniques for collecting O-D information from home and roadside interviews have historically been utilized to estimate O-D tables. However, these techniques are not only very costly, labor intensive, and disruptive to trip makers, but traditionally also do not capture traffic peaking behavior, which is often required for traffic operational purposes. Consequently, more cost-effective indirect or synthetic O-D estimation techniques have been developed, and continue to be developed. They utilize readily available traffic volume counts to estimate the most likely O-D tables that may have generated the observed link counts.

This thesis describes the basic formulations that have been proposed to formulate and solve the static O-D problem synthetically using link flow observations based on Maximum Entropy techniques. As is the case with many mathematical solutions to engineering problems, a number of simplifying assumptions have been made in order to solve the synthetic O-D problem. Unfortunately, the descriptions of these simplifying assumptions are often not fully described in the literature, and in some cases, these assumptions are not mentioned at all. Furthermore, the literature fails to systematically demonstrate what impact these assumptions have on the final O-D table estimate. Therefore, this thesis utilizes simple hypothetical networks to;

1. Demonstrate and compare the two main types of synthetic O-D formulations, namely the trip and volume based formulations.

2. Track the O-D estimation procedure from its initial formulation to its final formulation, demonstrating all significant assumptions that have been made and the implications of these assumptions on the final solution.

3. Demonstrate to what extent the final O-D estimation formulation remains valid when these assumptions are invoked.

4. Test the applicability of some packages which implement the various formulations and solution techniques that are available.

  Filename       Size       Approximate Download Time (Hours:Minutes:Seconds) 
 28.8 Modem   56K Modem   ISDN (64 Kb)   ISDN (128 Kb)   Higher-speed Access 
  Appendix.pdf 37.52 Kb 00:00:10 00:00:05 00:00:04 00:00:02 < 00:00:01
  Chapter1.pdf 16.45 Kb 00:00:04 00:00:02 00:00:02 00:00:01 < 00:00:01
  Chapter2.pdf 26.01 Kb 00:00:07 00:00:03 00:00:03 00:00:01 < 00:00:01
  Chapter3.pdf 77.26 Kb 00:00:21 00:00:11 00:00:09 00:00:04 < 00:00:01
  Chapter4.pdf 38.27 Kb 00:00:10 00:00:05 00:00:04 00:00:02 < 00:00:01
  Chapter5.pdf 38.34 Kb 00:00:10 00:00:05 00:00:04 00:00:02 < 00:00:01
  Chapter6.pdf 368.17 Kb 00:01:42 00:00:52 00:00:46 00:00:23 00:00:01
  Chapter7.pdf 11.36 Kb 00:00:03 00:00:01 00:00:01 < 00:00:01 < 00:00:01
  Etd.pdf 21.70 Kb 00:00:06 00:00:03 00:00:02 00:00:01 < 00:00:01
  Reference.pdf 14.07 Kb 00:00:03 00:00:02 00:00:01 < 00:00:01 < 00:00:01

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