Automating the Sequencing for the Montgomery County Bus Stop Listing Written and Presented By: Matt Yeh
Overview <ul><li>Montgomery County Transit publishes an annual report of all the bus stops in the County </li></ul><ul><li...
Data Sources <ul><li>Bus Stop point feature class </li></ul><ul><ul><li>Street name concatenated with type, direction </li...
Data Issues <ul><li>Bus Stop data </li></ul><ul><ul><li>Rife with street misspellings (name and type) </li></ul></ul><ul><...
Goals <ul><li>Merge street nomenclatures </li></ul><ul><li>Digitize and append missing street segments </li></ul><ul><li>C...
Interface <ul><li>VBA form within the ArcGIS Desktop environment </li></ul><ul><li>Input parameters </li></ul><ul><ul><li>...
1. Merge street nomenclatures <ul><li>Checks the on street of each bus stop against a master list of all street names from...
2. Digitize and append missing street segments  <ul><li>State street data was ultimately used since it was not segmented. ...
3. Correct street polyline direction <ul><li>In some instances, the direction of the street geometry did not match the dir...
4. Match the bus stop with the street centerline <ul><li>For each bus stop, the script would match the route number or str...
5. Intersect bus stop points with centerlines  <ul><li>A new temporary feature class was created and populated with points...
6. Generate a unique sequence number <ul><li>The script makes a call to the linear referencing tool from the geoprocessor ...
Presenting the data <ul><li>The official bus stop listing consists of two elements: </li></ul><ul><ul><li>The report listi...
<ul><li>The report listing </li></ul><ul><li>The listing was generated from a report created in Microsoft Access. </li></u...
2. The appendix maps <ul><li>The appendix consists of maps and an index map of the bus stop locations using a clean cartog...
Summary <ul><li>By automating the data behind the official bus stop listing, countless man-hours were no longer devoted to...
Questions ?
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Creating A 'Smart' Linear Referencing Tool

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Leveraging ESRI geoprocessing tools and ArcObjects classes, a 'smart' linear referencing tool was created to increase the level of accuracy of the data contained in the annual Montgomery County Bus Stop Book.

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Creating A 'Smart' Linear Referencing Tool

  1.  
  2. Automating the Sequencing for the Montgomery County Bus Stop Listing Written and Presented By: Matt Yeh
  3. Overview <ul><li>Montgomery County Transit publishes an annual report of all the bus stops in the County </li></ul><ul><li>Sorted by the on street of the bus stop in sequential order </li></ul><ul><li>Issues with the original process: </li></ul><ul><ul><li>Used arbitrary search radius parameters that matched stops with the incorrect street </li></ul></ul><ul><ul><li>Separated state and non-state roads and arbitrarily removed duplicate linearly referenced bus stops </li></ul></ul><ul><ul><li>Based sequencing on direction values that were often erroneous </li></ul></ul><ul><ul><li>In essence, assumed far too much and outputted poor results </li></ul></ul>
  4. Data Sources <ul><li>Bus Stop point feature class </li></ul><ul><ul><li>Street name concatenated with type, direction </li></ul></ul><ul><ul><li>From GPS coordinates </li></ul></ul><ul><li>County street centerlines </li></ul><ul><ul><li>Street name, street type, route number </li></ul></ul><ul><li>State street centerlines </li></ul><ul><ul><li>Street name concatenated with type, direction, route number </li></ul></ul>
  5. Data Issues <ul><li>Bus Stop data </li></ul><ul><ul><li>Rife with street misspellings (name and type) </li></ul></ul><ul><ul><li>Unreliable direction values </li></ul></ul><ul><ul><li>Bus stop points do not intersect centerlines </li></ul></ul><ul><li>County street data </li></ul><ul><ul><li>Segmented (optimized for address locating) </li></ul></ul><ul><ul><li>Unique street type nomenclature </li></ul></ul><ul><ul><li>Does not include road segments outside of the County </li></ul></ul><ul><li>State street data </li></ul><ul><ul><li>Mostly designated by state route number </li></ul></ul><ul><ul><li>Unique street type nomenclature </li></ul></ul><ul><ul><li>Direction of polyline (to and from points) did not match direction attribute </li></ul></ul>
  6. Goals <ul><li>Merge street nomenclatures </li></ul><ul><li>Digitize and append missing street segments </li></ul><ul><li>Correct street polyline direction </li></ul><ul><li>Match the bus stop with the correlating street centerline </li></ul><ul><li>Intersect bus stop points with street centerlines in preparation for accurate linear referencing </li></ul><ul><li>Generate a unique sequence number from linear referencing results </li></ul>
  7. Interface <ul><li>VBA form within the ArcGIS Desktop environment </li></ul><ul><li>Input parameters </li></ul><ul><ul><li>Bus stop layer (user specifies street value) </li></ul></ul><ul><ul><li>Road layer (user specifies street and direction values) </li></ul></ul><ul><ul><li>Output file location </li></ul></ul><ul><ul><li>Options to correct bus stop street spellings and street polyline direction </li></ul></ul>
  8. 1. Merge street nomenclatures <ul><li>Checks the on street of each bus stop against a master list of all street names from the street centerlines </li></ul><ul><li>If a match is not found, then it displays a list of similar street names from the master list </li></ul><ul><li>The user can either select from the list or type their own value. </li></ul><ul><li>The on street of the bus stop is updated to the user-generated value. </li></ul>
  9. 2. Digitize and append missing street segments <ul><li>State street data was ultimately used since it was not segmented. </li></ul><ul><li>Ride-On also serves stops outside of Montgomery County. </li></ul><ul><li>There were segments missing either because they were never digitized or they were lost when clipped. </li></ul>
  10. 3. Correct street polyline direction <ul><li>In some instances, the direction of the street geometry did not match the direction value in the attribute table. </li></ul><ul><li>If the option was enabled, the script would flip the line when necessary. </li></ul><ul><li>Some line segments had to be merged and the direction fixed if the road was disjointed. </li></ul><ul><li>Direction is important for accurate m-values during linear referencing. </li></ul>
  11. 4. Match the bus stop with the street centerline <ul><li>For each bus stop, the script would match the route number or street name to all streets within a 2000 foot radius. </li></ul><ul><li>This is to ensure that it does not get matched to another road with the same name. </li></ul><ul><li>This screenshot serves as a visualization. </li></ul>
  12. 5. Intersect bus stop points with centerlines <ul><li>A new temporary feature class was created and populated with points that intersected the centerline at a 90 degree angle to the original bus stop feature. </li></ul><ul><li>The new feature class kept the unique bus stop ID and street name from the original bus stop feature. </li></ul><ul><li>The direction was calculated depending on if it was to the left or the right of the centerline and was based on the direction attribute of the street centerline. </li></ul>
  13. 6. Generate a unique sequence number <ul><li>The script makes a call to the linear referencing tool from the geoprocessor object. </li></ul><ul><li>The results are filtered based on the unique road ID and the direction. It is then sorted by measure. </li></ul><ul><li>Sequence values are updated starting at 10 in increments of 10. </li></ul>
  14. Presenting the data <ul><li>The official bus stop listing consists of two elements: </li></ul><ul><ul><li>The report listing </li></ul></ul><ul><ul><li>The appendix maps </li></ul></ul>
  15. <ul><li>The report listing </li></ul><ul><li>The listing was generated from a report created in Microsoft Access. </li></ul><ul><li>The report is filtered alphabetically by the “on street” of the bus stop and sorted by the sequence number. </li></ul><ul><li>Other information includes the unique bus stop ID, at street, direction, location, amenities, routes serving, and the appendix map grid. </li></ul>
  16. 2. The appendix maps <ul><li>The appendix consists of maps and an index map of the bus stop locations using a clean cartographic style. </li></ul><ul><li>Maps are based on the ADC standards. </li></ul><ul><li>Utilized DS MapBook Extension </li></ul><ul><li>All geographic data is in Maryland State Plane, NAD83, US Survey Feet. </li></ul>
  17. Summary <ul><li>By automating the data behind the official bus stop listing, countless man-hours were no longer devoted to the QA/QC process. </li></ul><ul><li>A standardization of street data would have greatly improved the project with a very high degree of accuracy. </li></ul><ul><li>Further revisions: </li></ul><ul><ul><li>Still a work in progress and sometimes buggy (i.e., matching street names and generating next best matches) </li></ul></ul><ul><ul><li>Sequence bus stops in relation to the bus routes (not only street centerlines) </li></ul></ul><ul><ul><li>Rely solely on County centerlines </li></ul></ul><ul><ul><li>Adopt another component software interface standards (eg, CORBA) </li></ul></ul>
  18. Questions ?
  19. Thank You!

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