Click on Matrix 1 to highlight it then change its name (in the text box) to HBWFF. Change the names of Matrix 2 and Matrix 3 to HBOFF and NHBFF, respectively. Click OK and save the matrix file as ff.mtx. Note that a matrix file can contain more than one matrix (for example, ff.mtx contains three matrices: HBWFF, HBOFF, and NHBFF).
Step III: Fill the New Matrix with Friction Factors
The newly created matrix must be filLED with friction factors from the look-up table. For each of three trip purposes, the friction factors for a particular pair of origin and destination zones are determined by finding a Min_TT in the look-up table fflkup.dbf that matches the travel impedance between this pair of zones (based on the skim tree matrix). Travel impedances which are greater than the table maximum use the F-factor for the last category.
To fill the new matrix with friction factors, check that the following files are open (If closed, go to File / Open):
- Friction Factor lookup table (fflkup.dbf)
- Friction factor shell (ff.mtx)
- Skim Tree matrix (skimtree.mtx)
Go to Planning / Trip Distribution / Synthetic Friction Factors. The Create Friction Factor Matrix dialog box will appear; enter:
- Matrix File to Fill: Friction Factor Shell
With HBWFF highlighted, enter the following under Change Information:
