4.1.2 Appending Friction Factors
The trip distribution model requires not only production and attraction data, but also calibrated friction factors for the gravity model. Table 5 provides friction factors by trip purpose which were calibrated in an earlier modeling effort in Miasma Beach. Travel times which are greater than the table maximum utilize the F-factor for the last category. To create this friction factor matrix, first enter the friction factor look up table (Table 5) into TransCAD, and then create a new matrix file (to be filLED with friction factors). transcad will read the travel impedance matrix (skimtree.mtx) and look up Table 5 to fill the new matrix with friction factors.
Note: This model application will not utilize "socio-economic adjustment" K-factors.
Table 5. Existing Miasma Beach Friction Factors (2004)
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Friction Factor (Fij)
Time (min.) -------------------------------
HBW HBO NHB
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1 25 50 30
2 18 35 25
3 15 25 20
4 13 20 17
5 11 18 15
6 10 16 13
7 9 14 11
8 8 12 10
9 7 10 9
10 6 9 8
11 5 8 7
12 4 7 6
