PurdueUniversitySchool of Civil Engineering

CE 566 Tp. Planning HW6 = CAMPO2 / Posted: 14October 2013
Prof. Fricker / Due: Wed. 23October 2013

CE566 HW61Traffic Assignment

TRAFFIC ASSIGNMENT

You must complete this HW as a member of the team you joined for the CAMPO project. Each member of your team must sign the top page of the materials you submit for this HW. Your signature indicates that you have contributed to the contents of the materials that are submitted, that you will accept the grade given to the HW, and that you will be responsible for the subject matter covered by this HW on future tests.

For the problems below, submit only those portions of the TCW output that is needed to support your answers.

  1. (10 pts.) Network representation. TransCAD files that represent the example problem used in SNotes h/o 53 will be provided to you. Open the Map file “Eash2”. Notice the dummy links and centroid connectors that appear as dashed lines. In Figure 2 of h/o 53, there were only two nodes, even after Route C was added. Why did four new nodes and four new links have to be added in the TCW network?
  1. Iterative AON Assignment by TransCAD for Windows (TCW). Familiarize yourself with pages 173-183 and 186-187 in Chapter 9 of Travel Demand Modeling with TransCAD 6.0 (online) and Chapter 4 of the TransCAD Training Guide for Travel Demand Modeling. With file “Eash2.map” still open, open Matrix file “Eash2_OD”. After selecting Planning-Traffic Assignment,choose the “Capacity Restraint” method and 4 iterations in the dialog box. Store the resulting flow table as a binary file called “Eash2_Iterative”. When the “Results Summary” box appears, click on “Show Report”, then copy and save the linesbetween “Starting Procedure Traffic Assignment on …” and “Total Running Time …” as a text file called “Report_Iterative”.
  1. (10 pts.) In the joined dataview “Eash2_links+Eash2_Iterative”, compare the contents of the “AB_flow” field with the link flows in Table 2 of h/o 53. Are the flow patterns the same? If not, discuss the differences.
  2. (10 pts.) The VHT totals from TCW appear in the “Report_Iterative” file. They can also be obtained by applying Dataview-Statistics to the joined dataview. Try to verify the VHT totals from TCW using calculations by hand calculator or spreadsheet. Explain any differences and decide which Total VHT value to use.
  1. Incremental AON Assignment by TCW. Repeat Problem 2, but substitute “Incremental” for “Iterative” when naming output files. In the “Increments” window of the Traffic Assignment dialog box, replace “40 30 20 10” with “25 25 25 25”. From “Show Report”, save a text file called “Report_Incremental”.
  1. (10 pts.) In the joined dataview “Eash2_links+Eash2_Incremental”, compare the contents of the “AB_flow” field with the link flows in Table 3 of h/o 53. Are the flow patterns the same? If not, discuss the differences.
  2. (10 pts.) Try to verify the VHT totals from TCW using calculations by hand calculator or spreadsheet. Explain any differences and decide which Total VHT value to use.
  1. User Equilibrium Assignment by TCW. Repeat Problems 2 and 3, but use “UserEq” instead of “Incremental” or “Iterative” when naming output files. From “Show Report”, save a text file called “Report_UserEq”.
  1. (10 pts.) In the joined dataview “Eash2_links+Eash2_UserEq”, compare the contents of the “AB_flow” field with the link flows in Table 1 of h/o 53. Are the flow patterns the same? If not, discuss the differences.
  2. (10 pts.) Try to verify the VHT totals from TCW using calculations by hand calculator or spreadsheet. Explain any differences and decide which Total VHT value to use.
  1. System Equilibrium Assignment by TCW. Repeat Problem 4, but use the “System Optimum” Method and use “SystemEq” instead of “UserEq” when naming output files. From “Show Report”, save a text file called “Report_SysEq”.
  1. (10 pts.) In the joined dataview “Eash2_links+Eash2_SystemEq”, compare the contents of the “AB_flow” field with the user equilibrium link flows in Table 1 of h/o 53. Are the flow patterns the same? If not, discuss the differences.
  2. (10 pts.) Compare the System Equilibrium VHT totals with the User Equilibrium VHT totals that you decided to use in Problem 4B. Explain any differences.