Automating the Sequencing for the Montgomery County Bus Stop Listing Written and Presented By: Matt Yeh

Overview Montgomery County Transit publishes an annual report of all the bus stops in the County Sorted by the on street of the bus stop in sequential order Issues with the original process: Used arbitrary search radius parameters that matched stops with the incorrect street Separated state and non-state roads and arbitrarily removed duplicate linearly referenced bus stops Based sequencing on direction values that were often erroneous In essence, assumed far too much and outputted poor results

Montgomery County Transit publishes an annual report of all the bus stops in the County

Sorted by the on street of the bus stop in sequential order

Issues with the original process:

Used arbitrary search radius parameters that matched stops with the incorrect street

Separated state and non-state roads and arbitrarily removed duplicate linearly referenced bus stops

Based sequencing on direction values that were often erroneous

In essence, assumed far too much and outputted poor results

Data Sources Bus Stop point feature class Street name concatenated with type, direction From GPS coordinates County street centerlines Street name, street type, route number State street centerlines Street name concatenated with type, direction, route number

Bus Stop point feature class

Street name concatenated with type, direction

From GPS coordinates

County street centerlines

Street name, street type, route number

State street centerlines

Street name concatenated with type, direction, route number

Data Issues Bus Stop data Rife with street misspellings (name and type) Unreliable direction values Bus stop points do not intersect centerlines County street data Segmented (optimized for address locating) Unique street type nomenclature Does not include road segments outside of the County State street data Mostly designated by state route number Unique street type nomenclature Direction of polyline (to and from points) did not match direction attribute

Bus Stop data

Rife with street misspellings (name and type)

Unreliable direction values

Bus stop points do not intersect centerlines

County street data

Segmented (optimized for address locating)

Unique street type nomenclature

Does not include road segments outside of the County

State street data

Mostly designated by state route number

Unique street type nomenclature

Direction of polyline (to and from points) did not match direction attribute

Goals Merge street nomenclatures Digitize and append missing street segments Correct street polyline direction Match the bus stop with the correlating street centerline Intersect bus stop points with street centerlines in preparation for accurate linear referencing Generate a unique sequence number from linear referencing results

Merge street nomenclatures

Digitize and append missing street segments

Correct street polyline direction

Match the bus stop with the correlating street centerline

Intersect bus stop points with street centerlines in preparation for accurate linear referencing

Generate a unique sequence number from linear referencing results

Interface VBA form within the ArcGIS Desktop environment Input parameters Bus stop layer (user specifies street value) Road layer (user specifies street and direction values) Output file location Options to correct bus stop street spellings and street polyline direction

VBA form within the ArcGIS Desktop environment

Input parameters

Bus stop layer (user specifies street value)

Road layer (user specifies street and direction values)

Output file location

Options to correct bus stop street spellings and street polyline direction

1. Merge street nomenclatures Checks the on street of each bus stop against a master list of all street names from the street centerlines If a match is not found, then it displays a list of similar street names from the master list The user can either select from the list or type their own value. The on street of the bus stop is updated to the user-generated value.

Checks the on street of each bus stop against a master list of all street names from the street centerlines

If a match is not found, then it displays a list of similar street names from the master list

The user can either select from the list or type their own value.

The on street of the bus stop is updated to the user-generated value.

2. Digitize and append missing street segments State street data was ultimately used since it was not segmented. Ride-On also serves stops outside of Montgomery County. There were segments missing either because they were never digitized or they were lost when clipped.

State street data was ultimately used since it was not segmented.

Ride-On also serves stops outside of Montgomery County.

There were segments missing either because they were never digitized or they were lost when clipped.

3. Correct street polyline direction In some instances, the direction of the street geometry did not match the direction value in the attribute table. If the option was enabled, the script would flip the line when necessary. Some line segments had to be merged and the direction fixed if the road was disjointed. Direction is important for accurate m-values during linear referencing.

In some instances, the direction of the street geometry did not match the direction value in the attribute table.

If the option was enabled, the script would flip the line when necessary.

Some line segments had to be merged and the direction fixed if the road was disjointed.

Direction is important for accurate m-values during linear referencing.

4. Match the bus stop with the street centerline For each bus stop, the script would match the route number or street name to all streets within a 2000 foot radius. This is to ensure that it does not get matched to another road with the same name. This screenshot serves as a visualization.

For each bus stop, the script would match the route number or street name to all streets within a 2000 foot radius.

This is to ensure that it does not get matched to another road with the same name.

This screenshot serves as a visualization.

5. Intersect bus stop points with centerlines 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. The new feature class kept the unique bus stop ID and street name from the original bus stop feature. 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.

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.

The new feature class kept the unique bus stop ID and street name from the original bus stop feature.

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.

6. Generate a unique sequence number The script makes a call to the linear referencing tool from the geoprocessor object. The results are filtered based on the unique road ID and the direction. It is then sorted by measure. Sequence values are updated starting at 10 in increments of 10.

The script makes a call to the linear referencing tool from the geoprocessor object.

The results are filtered based on the unique road ID and the direction. It is then sorted by measure.

Sequence values are updated starting at 10 in increments of 10.

Presenting the data The official bus stop listing consists of two elements: The report listing The appendix maps

The official bus stop listing consists of two elements:

The report listing

The appendix maps

The report listing The listing was generated from a report created in Microsoft Access. The report is filtered alphabetically by the “on street” of the bus stop and sorted by the sequence number. Other information includes the unique bus stop ID, at street, direction, location, amenities, routes serving, and the appendix map grid.

The report listing

The listing was generated from a report created in Microsoft Access.

The report is filtered alphabetically by the “on street” of the bus stop and sorted by the sequence number.

Other information includes the unique bus stop ID, at street, direction, location, amenities, routes serving, and the appendix map grid.

2. The appendix maps The appendix consists of maps and an index map of the bus stop locations using a clean cartographic style. Maps are based on the ADC standards. Utilized DS MapBook Extension All geographic data is in Maryland State Plane, NAD83, US Survey Feet.

The appendix consists of maps and an index map of the bus stop locations using a clean cartographic style.

Maps are based on the ADC standards.

Utilized DS MapBook Extension

All geographic data is in Maryland State Plane, NAD83, US Survey Feet.

Summary By automating the data behind the official bus stop listing, countless man-hours were no longer devoted to the QA/QC process. A standardization of street data would have greatly improved the project with a very high degree of accuracy. Further revisions: Still a work in progress and sometimes buggy (i.e., matching street names and generating next best matches) Sequence bus stops in relation to the bus routes (not only street centerlines) Rely solely on County centerlines Adopt another component software interface standards (eg, CORBA)

By automating the data behind the official bus stop listing, countless man-hours were no longer devoted to the QA/QC process.

A standardization of street data would have greatly improved the project with a very high degree of accuracy.

Further revisions:

Still a work in progress and sometimes buggy (i.e., matching street names and generating next best matches)

Sequence bus stops in relation to the bus routes (not only street centerlines)

Rely solely on County centerlines

Adopt another component software interface standards (eg, CORBA)

Questions ?

Thank You!