HLR Section 3.2
Link Data
| CONTENTS
3.2.1 | Create & Edit Links
| (1) | Create a new Link
| (2) | Edit an existing Link
| (3) | Divide an existing Link & add a new Node
| (4) | Delete an existing Link
3.2.2 | Print Link Data
3.2.3 | Save Link Data to Database
| Other Links: | Main Index | Standard Routes | Analysis Routes | HL Route Network |
3.2.1 Create & Edit Links
| Links are created by specifying a link name, the node numbers at each end of the link and (optionally) a list of identification numbers for each structure lying on the link. A full descriptive title as well as a short abbreviated name for the link must be provided. Refer to Section 3.2.1(1) below for details. Links can be left "empty" if structure data is not available at the time the link is created - it can be added later as information comes to hand. Link numbers: A maximum of 3 alpha-numeric characters are permitted in the number. Zeros appended to the front of a number (such as "031") will be retained as part of the number. It is recommended that links should always be created first, before entering data relating to structures lying on those links. The reason is that one of the structure data attributes refers to the node number associated with the notional forward direction of the link (the Start node number - refer to Section 5.1.2 for a detailed explanation of this attribute.). If the link containing this number has not yet been created HLR will warn you that the node does not exist (although it will allow you to save the structure data). To create a new link use the "Link / Create a new link" menu options. To edit an exisiting link use the "Link / Edit an existing link" menu options. In either case the form shown below will appear.
| (1) Create a New Link To create a new link use the "Link / Create a new link" options from the main menu bar. The dialog box shown above will appear (with all fields blanked). Enter data as required. It is recommended that links should always be created first, before entering data relating to structures lying on those links. The reason is that one of the structure data attributes refers to the node number associated with the notional forward direction of the link (the Start node number). If this number does not exist HLR will give you a warning that the node does not exist (although it will allow you to save the structure data - refer to Section 5.1.2 for a detailed explanation of the notional forward link direction). The Start node will always be associated with the first span of a multi-span structure or the nearest abutment of a single span structure. All structures in the link must have the same associated Start node number, even if they lie on separate carriageways. Refer to Section 5.1.2 for a detailed explanation of this attribute. Mirror Links: When HLR creates a new link it will automatically create a link in the reverse direction. The link number, full name, abbreviated name and list of structures lying along the link will all be "flipped". This is done in order that the analysis can be performed for vehicles travelling in the reverse direction. When reversing the sense of the full and abbreviated names HLR uses the dash (-) and the word "to" (or "TO") as break points. For example, the link name "Murray Bridge to Bordertown" would be flipped to read "Bordertown to Murray Bridge" in the reverse link. Ditto for "Murray Bridge - Bordertown". If you do not require the reverse link (in a situation, for example, where the link you created represents an on/off ramp onto a freeway), you may either delete it manually from the HLL1.TXT and HLL2.TXT database files or ignore it. Refer to clause (2) below and to Section 3.2.3 , (saving link data to the database). Note: Links should not be created or edited when a job is still active - always clear the current application beforehand (go to the Job ID tab and click "Clear all data & b egin a new Application").
Updating Maps: If you have a map-based route selection system you will also need to add the new link to relevant map(s) and update all associated hotspots. Refer to Section 8.8, Customising Maps Used for Route Selection, for details.
| (2) Edit an Existing Link To edit an existing link use the "Link / Edit an existing link" options in the main menu bar. The dialog box shown in 3.2.1(1) above will appear (with all fields blanked). To retrieve the link you wish to edit, either click the button labelled "Select link from database" and choose the required link from the list, or enter the Start and End node number of the link you wish to edit then click "Get link data". In either case the remaining fields will be populated with the appropriate link data. This can be changed as required. Refer to Section 3.2.1(1) for further details. When resaving the edited data HLR will ask you whether you also want the reverse link to be also updated. (When HLR creates a new link it automatically creates a link in the reverse direction. This is done in order that the analysis can be performed for vehicles travelling in the reverse direction). If you elect not to do so at this point the system will only save the data for the currently selected link. You can always edit the reverse link at a later date if you wish. Refer to clause (2) below and also to Section 3.2.3 , (saving link data to the database). Note: Links should not be created or edited when a job is still active - always clear the current application beforehand. (To do this, go to the Job ID form and click "Clear all data & b egin a new Application").
| (3) Divide an Existing Link & Add a New Node The procedure described in this section divides an existing link into two "new" links. A new node is inserted at the juncture between the two sections. This procedure is typically used in situations where a new heavy load route is to join onto an existing route (other than at the ends of the route) or part of an existing link is to be separated and discarded. Select "Link / Divide an existing link & create new node" from the main menu bar. The dialog box shown below will appear (with all fields blanked). Although the process is largely automated, you will still need to manually enter some basic data and re-assign structure numbers between the two new "sub-links". Note: There is no Un-do facility! Once a link has been deleted it cannot be automatically restored.
| To divide an existing link enter the From and To nodes into their respective fields and the number of the new node to be inserted into the link (a maximum of three characters alpha-numeric characters is allowed). HLR will warn you if the specified link does not exist or one of the divided links already exists. If you have entered the From and To nodes in the wrong order HLR will give you a warning. In this case click the Clear button then re-enter the two node numbers in the correct order. Enter appropriate descriptions/names (full and abbreviated) for the two new links that will be created then re-assign structure numbers between them. Note that all structures from the existing (old) link are initially located in the left list box. Click on the first structure to be transferred. The Move right --> button will be activated. Click this button to move the highlighted structure number from the left-hand list box into the right-hand box. After this structure number has been moved the next number in the list is highlighted. Repeated clicking of the Move right --> key will allow you to quickly move the required structures into the right-hand list. If you inadvertently move a structure into the right-hand list, highlight it (by clicking on it) then use the Move left --> key to restore it to the left-hand list. Repeat for all other structure numbers that are to be assigned to the second link. Note that the final order of the structures in the right-hand list should be identical to the way in which they are physically located along the route, since the new From node for these structures will change.
Example: In the screen image shown above the From node for the first link (004-777) and for the structures on that link will now be 004 while for the second link (777-005) it will be 777. If the structures were to be evenly divided between the two new links the positive sense of structure numbers in the second link would be 2868 (already moved across) followed by 2675 then 2295.
Once all structures have been reassigned click the Save Changes button. HLR will create the two new links and save them to the database. For every structure lying on the second of the two new links HLR will also automatically update the node number identifying the notional forward direction of the link. Although a similar check will be performed for the first new link it will only report on structures for which the node is different to the From Node. You will, however, be given the opportunity of updating the nodes for these structures. HLR will also check and update all standard routes containing the old link and, if found, replace them with the two new links. Note, however, that if you do not require either one of the two new links in a particular route you will have to edit that route manually. Refer to Section 3.3.1(2), Edit a Standard Heavy Load Route, for instruction on doing this. Finally, you will be given the option of either retaining the old link or deleting it from the database.
Updating Maps: If you have a map-based route selection system you will also need to modify the map(s) and associated hotspots. Refer to Section 8.8, Customising Maps Used for Route Selection, for details.
| (4) Delete an Existing Link From the main options menu (top menu bar) select Link / Delete a link. A table of all links in the database will be displayed. Select the link you wish to remove and click the Delete button. Note that all link entries in the table appear in mirror-image pairs. For example, link number 004135 (SWANPORT - CALLINGTON) has a twin link called CALLINGTON - SWANPORT (number 135004). Both links will be deleted from the database. (The "twin" is created automatically by HLR to cater for travel in the reverse direction along the link). To delete a structure lying on the link refer to Section 5.7.4 To ammend digital maps (if they are used for route selection) refer to Section 8.8
3.2.2 Print Link Data
| To display and print a list of all links in the database click the Link option on the main menu bar then select List all links and nodes in database. A table of all links in the database will be displayed (ranked by node number) together with the number of structures in each link.
3.2.3 Save Link Data to Database
| Link data is stored in two ASCII (text) files in the ..\HLR\Database subdirectory as follows:
HLL1.TXT | Each row (or record) represents one link. The data fields in each row are comma delimited and represent the: Link number, full link name, abbreviated link name and the number of structures on the link. Data for each new link that you create (together with its associated reverse link) is added to the end of the file. If you wish to manually edit data in this file you may do so, but take care to also check for associated data in file HLL2.TXT. You may, for example, delete a reverse link but retain the main link.
HLL2.TXT | Each row represents a single structure number associated with the specified link. Data is comma delimited and saved in the following format: Link number, sequential order number along the link, structure number. Therefore, for each link the total number of records will equal the total number of structures in the link. Data for each new link that you create (together with its associated reverse link) is added to the end of the file. If you wish to manually edit data in this file you may do so, but take care to also check for associated data in file HLL1.TXT