Run Orders Continued from page 45 colors. These First Due polylines seem to cluster around their home stations. Verifying Relationships To verify First Due relationships, click Add Data and navigate to \Bonus_Files\SHPFiles\ CASP835F and load Optimized Travel Area.lyr. Place it at the top of the Run Order Group. This response area optimization was built from the same Redlands Streets using the functionality in Network Analyst to optimize service areas. Notice the alignment of First Due Streets and optimized response area boundaries, providing visual confirmation of the First Due run orders. Turn off First Due and turn on Second Due. Look closely at the home area for Redlands Station 261 and observe how Station 264 arrives second from the west, 263 comes in from the north, 262 fills in from the south, and Mentone 9 just reaches the eastern response area for Station 261 as Second Due. Check the Third, Fourth, and Fifth Due layers. Finally, let's map the arrival time difference between First and Second Due. Turn off all Due layers and make the Second Due minus First Due layer visible. Study the color relationships. Green lines represent short time intervals and red lines represent long intervals. Notice the large time differences for each station are in closest proximity to that station. Study the attributes to understand that the green lines in fringe areas are not entirely good. Even though the arrival difference is small, the First Due times often exceed five minutes. Look inside the City of Redlands. The time difference throughout much of the populated city is small, except in the most southern areas near Station 262 where all supporting responders must come from the north. As a bonus exercise, create thematic legends for all layers in the Run Order Group and design a separate map for each. Load these maps into Microsoft PowerPoint to create an informative slide show. Run Order Benefits and Limitations Run orders provide emergency responders with an accurate, reliable way to model complex responses with travel from multiple locations. This workflow counts on response from fixed facilities with all responders who are dispatched simultaneously. This method works well for a static, districtwide model that includes automatic and mutual aid. As mobile dispatching and automated vehicle locators (AVL) become widely deployed, this workflow will need to be simplified to speed up individual event dispatching. In more complex scenarios, appropriate lag times are applied to manually requested resources and volunteer responders to reflect additional time necessary for their departures. Also, unavailable units may be removed from the response stack. Apparatus types and personnel counts may also be included. As a word of caution in rural areas: when modeling long stretches of country roads, be sure to break street segments into appropriately short intervals. Acknowledgments Thanks to Chief Jeff Frazier and his staff at the Redlands Fire Department for providing fire station apparatus and personnel information and the staff of the City of Redlands GIS for the use of their excellent data. Special thanks to Tom Patterson and Russ Johnson at Esri for helping make this exercise a reality. For more information, take the Esri instructor-led course Working with ArcGIS Network Analyst. S T E P I N TO M Y O F F I C E . . . i t 's wher e th e r e a l w o r k h a p p e n s . Download your free mobile guide. w w w. c a r t e g r a p h . c o m / A U 9 . h t m l 800.688.2656 www.esri.com ArcUser Fall 2009