Run Orders Continued from page 41 and note the new fields: INDEX, CENT_X, CENT_Y, STAT_01, and TIME_01. All fields contain zero values but they will soon be populated with the arrival order and times for the five closest stations. Building the Network Dataset The next step is building the Redlands Network_Dataset in ArcCatalog. 1. Right-click on Run_Order_Model and select New > Network Dataset. Accept the default name, Run_Order_Model_ND, for this feature class. 2. Continue through the Network Dataset wizard, accepting defaults until you get to the wizard pane for specifying attributes for the Network Dataset. With Minutes selected, click the Add button. In the New Attribute dialog box, add a new attribute named Length_Mi and set its units to Miles and the Data Type to Double. Click OK. 3. Reselect Minutes. Click the Evaluators button and select the Default Values tab. Rightclick the Turn and choose Type > Global Turn Delay. Click Apply. 4. Press F12 to open the Global Turn Delay Evaluator and type in the delay parameters shown in Table 1. Click OK and OK again to return to the dialog box for specifying attributes. 5. Click Next to continue and accept the directions defaults. 6. Click Next, select the summary text, copy and paste it to a WordPad document, and save that document with the project. 7. Click Finish and build the network. Inspect it when ArcCatalog has finished processing. Creating Indexes, Generating Centroids, and Exporting Data 1. Close ArcCatalog and open ArcMap. Navigate to the \Redlands folder and open Redlands01.mxd. Switch from Layout View to Data View. 2. Open the attribute table for the Streets with Speed layer. Scroll to the right, study the fields, and locate the INDEX, CENT_X, and CENT_Y fields. 3. Right-click on INDEX and open the Field Calculator. Double-click on OBJECT_ID1 to add it to the formula box. Click OK to populate this field with a sequential index. 4. Right-click on the header for CENT_X and select Calculate Geometry. Choose X Coordinate of Centroid to perform this calculation. Use the data frame coordinate system (NAD 1983 StatePlane California V FIPS 0405) and Feet US as the units for this project. Click OK. This tutorial models response from fire stations in and near Esri's headquarters in Redlands, California. Direction Straight Straight Reverse Right Turn Left Turn Description From Local to Local Road across No Roads From Local to Local Road across Local Road From Local to Local Road From Local to Local Road From Local to Local Road Seconds 0 1 30 2 4 Table 1: Delay parameters Specify another attribute for the network dataset called Length_Mi. With Minutes selected, click the Add button and set its units to Miles and the Data Type to Double. 5. Repeat this procedure for CENT_Y to calculate values for the Y Coordinate of Centroid field. Inspect the calculations and save the project. 6. Now, export this table to a dBASE file so these points can be used to map street centroid points. In the Attributes of Streets with Speed table, click the Options button and select Export. Specify All Records and save the table in the \Redlands\DBFFiles folder as Network_Street_Centroids_XY.dbf. Click on the Source tab of the table of contents (TOC) and add the table to the map. Mapping Incidents The ArcGIS Network Analyst extension Closest Facility solver requires two input datasets: Locations and Facilities. To build run orders, load Fire Stations as Facilities and the street segment centroids as Incidents. Determining the five closest facilities to each centroid Incident will involve considering seven possible Facilities and almost 6,500 Incidents, so this model might take some time to run. On the Source tab of the TOC, right-click on Network_Street_ Centroids_XY.dbf and select Display XY Data. In the Display X,Y dialog box, set the X Field to CENT_X and the Y Field to CENT_Y. Click OK. After processing is complete, open the www.esri.com ArcUser Fall 2009