Global Data
Global DataThis option provides an extensive sub-menu with the options needed to define the scope and parameters of the analysis project. From here the user defines the scenarios to be analyzed, specifies which reports are to be included in the output files, enters the titles that appear on each page of the output reports, selects or enters parameters to be used in the level of service analysis, names and selects the trip generation rates to be used, names and selects the trip distribution percentages to be used, and names the output and log files produced by the forecast run. The Global Data menu can also be accessed as a pop-up menu using RightClick while pointing to a blank spot in the network editing window.
Choose this option to define alternate analysis scenarios, using multiple data sets. The Edit Scenarios dialog box is shown below. To define scenarios follow the steps outlined below.
Name the desired scenarios. Click the “Scenario” button and enter the different scenario names your project requires. For instance, “AM Peak Hour” and “PM Peak Hour”. This scenario name is printed on each page of the forecast output reports and is shown in the title bar of the network editing window.
Name the alternate data sets that will be used. Click the respective data set buttons to specify a separate name for every type of data set that will vary from scenario to scenario. For instance, AM and PM data sets for Volume, Trip Generation, and Trip Distribution. You might also want to name separate AM and PM Mitigated scenarios and separate existing and mitigated Geometry data sets. If you want different titles and output files for each scenario, you will need to name separate Command data sets for each scenario. (Users familiar with the DOS version of the program should note that TRAFFIX for Windows stores titles in the Command data set, not the Configuration data set.)
Figure 33 Edit Scenario Dialog Box
Specify which data sets will be used for each scenario. The scenario shown in the “Scenario” drop-down box is the scenario being edited. With the desired scenario name in the Scenario drop-down box, use the arrows on the respective drop-down boxes to show the data sets that will be associated with this scenario. Then do the same with the other scenario names in the Scenario drop-down box.
Exit the Edit Scenarios dialog box.
The functions of the various data set buttons on this dialog box are as follows:
This feature affects the TRAFFIX software specific items such as; Titles, Global LOS Methods, Calc. Sat Adj, Report Only Selected Intersections, Lock Network, and Comment Lines (on the Options… Global Data … Parameters & Titles dialog screen) and Output File Name, Log File Name, Reports, Compute Delay (on the Options…Global Data menu). For example, if separate command data sets are named, each scenario can also have its own Output File name and Log File name if the user desires (these are accessed from the Options…Global Data menu).
This button allows the user to name different base volume data sets for each scenario.
This button allows the user to name different intersection geometry data sets for each scenario.
This button allows the user to name different impact fee data sets for each scenario. In this way, there can be different mitigation measures and costs, and different impact fee calculations performed for each scenario.
This button and drop-down box does not create and select trip generation rates. But if the user wants to have different generation rates for different scenarios, then separate data sets must be named here and associated with each scenario. This also allows for different trip generation titles, which are entered on the Options…Global Data…Parameters & Title dialog box. If you do not name separate data sets for each scenario, then the last generation rate to be selected (regardless of which scenario is active) will be used for all scenarios.
The actual trip generation rates are not available until the following two steps have been completed.
Name and select generation rates for a given scenario, using the Options…Global Data…Trip Generation Rates dialog boxes.
Enter trip generation rates, using the Trip Generation option on the zone pop-up menu (accessed with RightClick when the mouse cursor is over a zone).
This button and drop-down box does not create and select trip distribution percentages. But if the user wants to have different distribution percentages for different scenarios, then separate data sets must be named here and associated with each scenario. This also allows for different trip distribution titles, which are entered on the Options…Global Data…Parameters & Title dialog box. If you don’t name separate data sets for each scenario, then the last generation rate or distribution rate to be selected (regardless of which scenario is active) will be used for all scenarios.
The actual trip distribution percentages are not available until the following two steps have been completed.
Name and select distribution percentages for a given scenario, using the Options…Global Data…Trip Distribution Percentages dialog boxes.
Enter trip distribution percentages, using the Trip Distribution option on the zone pop-up menu (accessed with RightClick when the mouse cursor is over a zone).
This button allows the user to name different path percentage sets for different scenarios. Only one set of paths is available to all scenarios; however, by defining several paths and assigning varying percentages to each path (in the Edit Paths mode), the user can create different paths for each scenario. A path can be turned off by assigning it a “zero” percentage.
This button allows the user to name different arterial analysis route sets for each scenario. Only one set of routes is available to all scenarios; however, the “Evaluate? Yes/No” field (accessible in the Edit Routes mode) can be used to turn routes on or off for a given scenario.
This feature affects traffic operations and analysis specific factors and parameters, including Vol. Adj, Growth Factor (G.F.), Delay Adj, Delay Parameters, Max. Cycle, Population, Metric Units, G/C vs. Green time, and LOS Grade Modifier (on the Options… Global Data … Parameters & Titles dialog screen), and LOS Parameters (on the Options…Global Data menu), and local intersection LOS Method (from the intersection pop-up menu via Geometry…Signal Timing). If separate configuration data sets are named, each scenario can have different values for these items. One of the more common uses of a scenario specific configuration file would be the creation of a future long-range forecast scenario that would apply a growth factor to a set of existing turning count volumes. Note that this growth factor adjustment rate is applied to the base volumes and the base volumes with project traffic volumes.
The active scenario for editing and analysis is that shown in the Scenario drop-down box in the upper left corner above the network window in Edit Network mode. All of its associated data sets are active, and any changes made (while in the Network, Paths, or Routes edit modes) affect only that scenario, unless the data set involved in that change is shared by other scenarios.
TRAFFIX for Windows uses only one network for all of the scenarios in the database. Therefore, any changes made to the network (adding/deleting intersections, links, gates, zones) will apply to all scenarios. If your analysis problems require alternate networks, you should create separate databases, each with a different network. This means that a given intersection can not be unsignalized in one scenario and signalized in another scenario. If you change it from unsignalized to signalized, the change will take effect in all scenarios.