Road Repairs Continued from page 57 the SplitLinesAtPoints module to view the VB code. No changes are required to this code. Close VB Window. Save the ArcMap document now to save this script in this project. To run the script in ArcMap, verify that the polyline target (Chuckanut Ridge Road) and the splitting points (StartPoints and Endpoints) are in the TOC. Zoom to Bookmark CR All 1:12,000. Choose Tools > Editor toolbar to load the Editor toolbar, and choose Editor > Start Editing from the drop-down menu. Select the \Chuckanut2\SHPFiles\WASP83NFH\ folder as the folder to edit data from. Make both StartPoints and Endpoints the only selectable layers. Use Zoom Out and the Selection tool or use the table to select all 47 points. In the Tools Menu, choose Macros > Macros > Select SplitLinesAtPoints and click Run. Review the summary windows to see how many points were used to split the road and how many splits occurred. This will actually split the road twice, using both Event Theme sets. Save the edits and the project. After making the event themes, StartPoints and EndPoints, the only selectable themes, select all points and run the SplitLinesAtPoints script. 6. 7. 8. 9. Summary This exercise is an extension of "Under Construction: Building and Calculating Turn Radii" in this issue. It teaches how to derive endpoints for polyline segments and how to use the points to split one or more polylines into smaller segments. This workflow has many uses beyond transportation engineering. Acknowledgments The author thanks Esri's Technical Support team for helping develop and deploy this method. An enhancement request has been submitted for this task and several related tasks that also surfaced while developing this exercise. Task 5: Assign Turn Numbers Reload the Turn Chords layer and add the Middle Ordinate layer and make Chuckanut Ridge Road the only selectable layer. Use CR MP 0.01:3,000 to zoom to the south end of the road. Use the Turn Chord layer as a guide to select the first turn segment. Either open an editing session to manually assign turn numbers or use the Field Calculator to populate the Turn_No field. Notice that ArcMap labels the segment as the number is assigned. Continue assigning numbers to all 47 turns. Although these turns do not have to be numbered sequentially, it does help keep turn numbers straight. Finish the Project When finished assigning numbers, open the attribute table and sort the turn numbers in ascending order. After assigning turn numbers, to reinforce an important point from the original tutorial, join the lengths of the Turn Chord and Middle Ordinate to each road segment. Next, calculate the radius of each turn and thematically map each using the color ramp used in the original exercise. Save the finished project. Master of Science in GIS at the University of Redlands O ur MS GIS Program is designed for an audience of professionals seeking to improve their knowledge of the analysis and management of geographic information. We offer both a full-time and a part-time residential program. Within the University's interdisciplinary learning environment, students have an unparalleled opportunity to interact personally not only with University faculty, staff, and students from other programs, but also with the many talented professionals at the world's leading GIS company, Esri, located in close proximity to the University. The University of Redlands, founded in 1907, is a fully-accredited, liberal arts and sciences university. This intensive, international learning environment ensures a global context of relevance to students from around the world. Graduates of this program can become GIS practitioners prepared for positions such as project managers, applications specialists, and applications software development team members. For information call (909) 748-8128 or visit www.msgis.redlands.edu 58 ArcUser Winter 2010 www.esri.com