When the highway network geographic file is editted (e.g., adding or deleting links) or update link attributes (e.g., changing link speeds or capacities), the network file is NOT updated automatically. The network file must be re-created. The most recent network created is the active network and remains in memory and ready to use until it is actively changed. The name of the active network is displayed in the status bar at the bottom of the transcad program window. [References: See User's Manual (pp. 299-305)].
2.2 Develop 2004 Base Year SKIM Trees with transcad
Three steps are required. First, the actual Interzonal minimum paths are computed. Intrazonal travel times cannot be computed directly from the network, thus, a second step involves approximating these times from interzonal times to neighboring zones. Finally, terminal times are optionally appended to selected zone pairs.
Produce a minimum tree schematic for at least one centroid. These schematics will help identify any network errors; if any are found, correct them immediately (and repeat earlier tasks as necessary). A sample network tree is in Figure 2.
+---------------------------------------------------------------+
| ----- link is on minimum path tree
