CHAPTER 16: THE EDIT NETWORK SCREEN

This screen is used to draw and edit the network and access the Intersection, Zone, and Link pop-up menus. Drawing and editing a network is a very simple task. This is the default screen when the program starts. A toolbar appears on the left of the network editing window, including the ten network drawing/editing tools shown in Figure 46.

Figure 46 Drawing Tools

Some of these tools have options associated with them. To view or change these options simply place the cursor over the tool icon and RightClick. This will bring up a dialog box with the available options. For example, the three intersection tools (signalized, four-way stop, and unsignalized) have the options to display the intersection index only, the index and the base LOS, the index and the future LOS, or the LOS only for the base or future case. (Note that when the future LOS is displayed, an asterisk is also displayed to differentiate it from the base LOS.) They also have options to select or unselect all intersections for LOS evaluation.

There is also an option to Disable Text Scaling of the text items (index numbers & LOS values), so that they remain readable at all zoom scales. All node tools also have the option to draw one-way or two-way links automatically as nodes are placed. If the Ctrl key is held while selecting an option, that selection will apply to all tools with that option.

The picture tool allows the user to place a graphic image on the workspace to aid in the placement and scale of nodes and links. The Transparent options associated with the Picture Tool and the Text Tool serve to limit object edits to the specific object tool. Thus if the TEXT tool Transparent option was enabled, only the TEXT tool would be able to edit text objects.

The text tool also has the option to Embed Fonts. This option allows users to include (within the TFX document) custom (i.e., TrueType PostScript) fonts and symbol sets. Note: Some digital font developers have restrictions on font embedding.

To draw a network, simply click on the tool you wish to use and then click in the network window where you want to position the item selected.

Intersections, zones, and gates are positioned by clicking once. The intersections, zones, and gates will be numbered automatically in the order that you insert them. These index numbers can be changed later if desired using the “Change Index Number” keystroke Ctrl-RightClick or from the node and zone pop-up menus.

Links can be drawn automatically as the nodes are placed, by selecting this option from the node tools. Either one-way links or two-way links can be drawn (holding the Ctrl key while placing nodes will temporarily toggle from one-way to two-way, and vice versa). Nodes are selected (highlighted) as they are placed. Links are drawn from the last selected node to the newly placed node, or to an existing node if you click on one. To draw a link between two nodes already placed (but not the last one placed) first unselect all nodes (Ctrl-A), click on one of the existing nodes, and then click on the other existing node.

Links can also be drawn using the Link tool. In this method, links are positioned by clicking a node, moving the cursor to another node, then double clicking. If you are drawing one-way links (default), a one-way link will be drawn from the first node to the second. To draw two-way links, hold the Ctrl key while drawing the link. Press Esc to turn the Link tool off and cancel the link currently being drawn.

A link can be defined as either Straight or Curved. Most users will not need to emulate curved links. However, links can now be curved to more accurately represent reality. A link may be curved in order to lengthen it.

Text is positioned by clicking once to place an empty text field, then with the cursor over the field, Right Click to bring up the text dialog box.

Approximate positioning of nodes is generally adequate for TRAFFIX analysis purposes.

If more precise spatial accuracy is desired, the user may wish to utilize a picture underlay.

Drawing is aided by the position coordinates, shown below the lower right corner of the network window. These are the coordinates of the cursor position. The options provided under the Arrange menu are also useful for aligning nodes after they have been placed. There is also a “Snap to Grid” option which can be turned on or off from the File…Preferences menu selection, The user can specify the size of grid spacing to be used. This is especially useful for drawing orthogonal street networks.

To delete an item, point to it and use Ctrl-Shift-LeftClick . To confirm that you are selecting the item you want, watch the item selection line below the lower left corner of the network window. Nodes, zones, and gates can be also be deleted from the pop-up menu that appears using RightClick while pointing at the item. Other options available from these pop-up menus include changing the node index number and selecting the node for evaluation. When a node is deleted, all links attached to it are also deleted.

Links can be drawn at any angle desired; however, no intersection (zone or gate) can have more than four legs. When drawing links on an angle, pay careful attention to which side of the intersection (zone or gate) box the link is being attached. (This can be seen more easily if you zoom in on the intersection, so that each individual one-way link is visible.) Only one link in each direction is allowed to be attached to each side of these boxes.

Intersection, zones, gates, and text can be moved using LeftClick-Drag . The attached links move along with these items automatically. To reorient text, choose the text tool, point to one end of the text field until the curved arrow rotation icon appears, then LeftClick and drag the text base line to the orientation desired and release. The text will then appear in the new orientation.

Links can be repositioned using LeftClick-Drag with the cursor near the end of the link to be moved. Select the Link tool and position the cursor on the link near its end. Look for the small square handle to appear then LeftClick-Drag the end of the link to its new position (another node or another side of the current node).

At small scales (zoomed out), you can confirm that you are selecting the item you want by watching the item selection line below the lower left corner of the network window. The item selection line shows the item’s index number, connection points, name, and selection status.

To change an intersection’s type, first select the tool that corresponds to the new type (signalized, cross street, unsignalized, 4-way stop), then click on the intersection to be changed. Note: This changes the intersection type for all scenarios.

The Cut, Copy, and Paste options under the Edit menu can be used to modify networks. The Cut option deletes selected (highlighted) items from the network, and also places a copy on the clipboard. The Copy option copies selected items to the clipboard. The Paste option inserts from the clipboard items previously placed there with the Cut or Copy options. The Duplicate option does the Copy and Paste options in one step. The Paste option can be used to copy items from one network to a new network, and it can be used to copy items in one network to the same network. In the latter case, the new item is placed near the existing item and must be moved to its new location. When the Copy or Duplicate function is used within a single database, intersection data for all scenarios are copied to the new intersections. When used to copy from one database to another, the Copy function cannot copy data for all scenarios, because the scenario definitions may not be identical. To copy scenario data from one database to another, first define the scenarios for the new database, then the use Tools…Copy Database Data…By Scenario feature. Similarly, path and route data cannot be transferred to a new database using the copy and paste features.

The Delete key will also remove items from the network, but they are not placed on the clipboard and cannot be retrieved with the Paste command.

Note: The Cut, Copy and Delete keystrokes act on ALL items in the network that have been selected (highlighted) for editing. It is easy to inadvertently select extraneous items in portions of the network that are not presently displayed on the screen. Therefore, it is good practice to unselect all items before starting a Cut, Copy, or Delete operation. There are Select All and Unselect All options on the E dit pull-down menu, which are useful when doing successive cut or copy operations.

The entire network can be printed using the File…Print menu option. The dialog box allows the user to specify the print scale, select “Scale to Fit Page”, or specify multiple print copies. To print only the portion of the network displayed in the editing window, choose File…Print Window.

It is generally easier to code extra links (for future facilities) into the base network, than it is to add new links to an existing network data set.

It is highly recommended that zones and gates be connected to a network with at least two links. In this way, an additional zone or gate can be added later that has the same access to the network. The link connected to a zone or gate cannot be split with an intermediate node.

After links are created, nodes can be added between the two end points; and the original link will automatically be divided. This feature is convenient for making unanticipated changes to networks but should only be used when necessary. The insertion of nodes will not affect existing paths or routes in memory; however, an exception to the ability to split links involves links connected to either a gate or zone. TRAFFIX is unable to adjust the paths and routes if a node is inserted at such points, and the affected paths and routes will have to be redrawn. TRAFFIX is also unable to adjust the network if a node is deleted. New links will have to be created, and all paths using the links that were deleted will have to be redrawn.

Users who wish to create networks that consistently use an altered set of parameters that vary from the TRAFFIX defaults have two optional approaches to use. One is to create a starter template database with all of the user’s preferred global default settings and including one or more template intersections containing the preferred local default settings. The user can then begin each new project by starting with this starter database and copying the template intersections as many times as needed. Another approach is to use the default database procedures in connection with the Preferences settings. See CHAPTER 6: THE FILE MENU for additional information on these procedures.