Appendix A

PEGGER Software Manual

About this Manual
This manual is designed to help new users install and run PEGGER in ArcView 3 GIS. While PEGGER will work on all ArcView 3 platforms, this manual was written specifically for Microsoft Windows. Users of other platforms will still find this manual valuable, but will have to make the appropriate translations when necessary. Some of the content in this manual comes directly from the ArcView 3 help system and is included here as a convenience to the user.

Installing PEGGER
PEGGER can be downloaded from the Rural Technology Initiative website at http://www.ruraltech.org/tools/PEGGER. Download the setup.exe file or run it directly from the web to start the installation. On the first page of the setup program, select Next to continue.

Read the terms of the license agreement and select ‘I accept the agreement’ if you wish to install the software. Select Next to continue.

Select a location for PEGGER to be installed. Most of the files that PEGGER installs will be in the ArcView installation directory so less than 1 MB of files will be placed in the installation directory chosen here. Accept the default location and select Next to continue.

All installations will include the PEGGER ArcView extension and the integrated help files. If you do not wish to install the tutorial, select Minimal. The Compact installation includes the PEGGER tutorial with only the three shapefile datasets for those who do not have Spatial or 3D Analyst. The Full installation includes the PEGGER tutorial and all the tutorial datasets: three shapefiles, a GRID elevation model, and a TIN for those who have Spatial or 3D analyst and wish to use the Survey P-Line function with RoadEng.

Select a folder to place the program shortcuts in the start menu. Either the default location or the ESRI\ArcView GIS 3.x folder work well.

Review the installation settings and select Install to complete the installation.

A completion screen will appear if you have installed PEGGER successfully.

You should now have a new item under your start menu called PEGGER with shortcuts to the PEGGER Tutorial, the PEGGER Help file and the un-installation program depending on which installation components were selected.

Uninstalling PEGGER
To uninstall PEGGER, use either the Uninstall PEGGER function in the PEGGER folder under the Start menu or use Add/Remove Programs in the Control Panel. Select Yes when prompted to remove the software.

Finding Help
Installed with PEGGER are a complete set of help files that are integrated into the ArcView help system. In addition, a shortcut to the PEGGER help can be found in the PEGGER folder under the Start menu. A good place to start learning about PEGGER is in the table of contents under Extensions > PEGGER > Getting Started.

All of the tools, dialogs and menus that are part of the PEGGER extension have context based help that can be viewed in the status bar at the bottom of the ArcView application window. In addition using the View Help tool: and clicking on any PEGGER control will bring up the appropriate page in PEGGER Help.

Using Tutorial.apr
Included with the Full or Compact PEGGER installation are a tutorial.apr project file, pegger_trans.shp, pegger_cont.shp and pegger_hydro.shp shapefiles. If you have ArcView Spatial Analyst or 3D Analyst and chose the Full installation option, then you may also have a pegger_dem GRID and a pegger_tin TIN.

The tutorial project file opens with the three shapefiles already symbolized and added to a view. If you have Spatial Analyst or 3D Analyst you can also add the DEM or TIN to the view. First, enable the Spatial Analyst or 3D Analyst Extension by selecting Extensions under the File menu and selecting 3D or Spatial Analyst.

Then, using the Add Theme Button: browse to the AVTUTOR\PEGGER directory, select Grid Data Source or Tin Data Source for the Data Source Type, and select pegger_dem or pegger_tin.

Activating the Extension
To Activate the PEGGER extension you must select it in the Extensions dialog box. To open the Extensions dialog box, select Extensions under the File menu. Select PEGGER and any other extensions you wish to use and OK the Extensions dialog box. If you want PEGGER to be available each time you open ArcView, select PEGGER and then check the Make Default box on the right.

The road theme

Grade attribute
PEGGER can keep track of grade information as roads are pegged. In order for PEGGER to keep track of grade information there must be a numeric field in the attribute table that can store the grade information. If you want to keep track of grade information as you peg, check to make sure an attribute already exists that will work, or add a new attribute to the table.

Open the attribute table for the road theme by making the road theme the active theme (select it in the view legend), and selecting Theme > Table or by using the Open Theme Table button:

Look at the fields in the table to determine if there is an appropriate field for storing grade information. In this case, the Grade field looks like it will work, but it is always good to check to make sure it is a numeric field. Select the Grade field and look under the Field menu. If the statistics menu item is not grayed out, then it is a numeric field (it will be grayed out if it is a text field).

If you want to add a new field to the table to store grade information, you will need to start editing the table, and then add a new field of type number. If you would like more information, lookup “editing a table” in the ArcView help file index

Name attribute
In addition to storing grade information as roads are being pegged, road name information can also be saved. In order for PEGGER to keep track of road name information there must be a text (a.k.a. string) field in the attribute table that can store the road name information. If you want to keep track of road name information as you peg, check to make sure an attribute already exists that will work, or add a new attribute to the table.

Open the attribute table for the road theme by making the road theme the active theme and selecting Theme > Table or by using the Open Theme Table button:

Look at the fields in the table to determine if there is an appropriate field for storing road name information. In this case, the Road_id field looks like it will work, but it is always good to check to make sure it is a text field. Select the Road_id field and look under the Field menu. If the statistics menu item is grayed out then it is a text field.

If you want to add a new field to the table to store road name information, you will need to start editing the table, and then add a new field of type string. If you would like more information, lookup “editing a table” in the ArcView help file index.

The contour theme

Elevation attribute
PEGGER uses a contour theme as a representation of the ground surface. While this could have been done on a raster dataset or on a Tin, both of those options would have required access to either the Spatial or 3D Analyst Extension. To make the program as simple and inexpensive to use as possible, contours are used.

In order to use a contour theme with PEGGER, a numeric attribute in the contour theme must store the elevation values of the contours. Check to make sure that the contour theme has a numeric elevation value field by opening the table and looking at the themes attributes.

If the contour theme attribute table does have an elevation field but the values are stored as strings rather than numbers, they will need to be converted before being used with PEGGER. For more information, lookup “elevation data” in the ArcView help file index.

Contour Interval
The contour interval of the contour theme is an important consideration when locating roads using PEGGER. For large-scale (small area) pegging, a smaller contour interval should be used in order to more accurately represent the ground surface. For small-scale (large area) pegging, a larger contour interval should be used to more efficiently analyze larger areas of land. The trade-off is accuracy vs. speed. Smaller contour intervals mean more contours and more data. The spatial and attribute queries that PEGGER uses to locate routes slows considerably with larger datasets.

Subset data
If you are working over a large area but need the accuracy of a small contour interval, consider using a subset of your larger contour dataset. To create a subset of your contour dataset, make the contour theme the active theme and use the selection tool:

After selecting the contours in the area you will be pegging, select Theme > Convert to Shapefile and save the new dataset. This dataset will automatically be added to the active view and displayed.

Create an index
To speed up the pegging process, create and index on the elevation item in the contour attribute table. Open the attribute table for the contour theme by making the contour theme the active theme and selecting Theme > Table or by using the Open Theme Table button:

Select the elevation attribute field heading and then choose Field > Create Index to create the attribute index. If the there is a Remove Index instead of Create Index under the Field menu, then the elevation attribute is already indexed.

Dissolve contours
Some contour themes may have more contour line features than are necessary to accurately represent the ground surface. Using the Dissolve Lines option under the Roads menu can improve the performance of PEGGER.

Make the contour theme the active theme and select Dissolve Lines under the Roads menu. When asked, select the elevation field in the contour dataset as the field to dissolve on.

Optionally, you can select additional fields to summarize in the output attribute table. If you don’t want any additional fields to be summarized, select OK.

Choose a location to store the output shapefile.

Additional Themes

You may wish to add additional datasets to the view for use while you are pegging. Streams, slope class information, existing roads, unstable slopes are all common datasets that may be added into the view in order to better inform the pegging process.

Setup Pegger
Once you have both the contour and road themes added to the view, you need to setup PEGGER so that it knows which contour theme to use with each road theme. You can have multiple road themes and multiple contour themes in the same view. PEGGER stores setup information with each road theme. This way, you could have contour themes and road themes for varying scales.

To setup PEGGER, make the desired road theme the active theme and select Setup Pegger from the Roads menu. You can setup PEGGER both inside and outside of a pegging session. Selecting Setup Pegger will open the PEGGER Setup dialog where you can select a contour theme to use and whether or not to add grade and road name information to the attribute table while pegging.

First, select the Contour Theme that you will use as the elevation model for your work area. Once you have selected a contour theme the Elevation Field will be populated with numeric attributes from the contour theme attribute table. For more information about the required attribute format, see Elevation Item in the Contour Theme section. Select the field in the attribute table that stores the elevation information for each contour.

Once an elevation field is selected, PEGGER will attempt to determine the contour interval of the contour dataset. If PEGGER can not determine the contour interval then it can be manually entered in the Contour Interval box. Optionally, PEGGER can keep track of grade and road name information in the attribute table of the pegged road theme. The grade and road name information can be helpful in performing additional analyses in the GIS or for truck performance modeling, costing, etc. If desired, select the options to store this information as new road segments are added to the road theme. If you have a large road theme dataset, this can cause the performance of PEGGER to be affected. This feature can be turned on and off as desired.

Snapping
Once PEGGER Setup has been run a notification dialog may appear with snapping tolerance information. Snapping is the ability of a newly added feature to be “snapped” or connected to existing features. If snapping is not enabled, or set improperly, newly added features may not connect to existing features. For this reason, PEGGER sets up a default snapping environment for you. If you would like additional information about the ArcView snapping environment select yes at the prompt or lookup “snapping” in the ArcView help system index.

Start Editing the Road Theme

ArcView allows you to edit a theme that is based on an ArcView shapefile if you have file write permission on the shapefile.

To make a shapefile theme editable
Make the shapefile theme active. Choose Start Editing from the View's Theme menu or Start Pegging from the Roads menu. ArcView allows you to edit only one theme in a view at a time. If you choose Start Editing or Start Pegging on a theme while you are editing another theme, you will be prompted to save your edits on the theme you were previously editing before editing on the second theme is enabled. A dashed line around the theme's check box in the Table of Contents indicates that you can edit that theme.

To undo and redo edits
Choose Undo Feature Edit from the Edit menu to undo the last edit you made to the shapefile. Choosing this option repeatedly enables you to successively undo all the edits you made since you started editing. Undo Feature Edit undoes changes to the feature geometry in the shapefile and the corresponding changes to the feature attribute table. The Redo Feature Edit option let you re-apply the changes.

To save your edits and continue editing
Choose Save Edits from the Theme menu to save all edits made to the theme during the current edit session. Once you save the edits, you can continue to edit the theme but you are not able to undo or redo any edits that were made prior to choosing Save Edits.

To save your edits out to a new theme
Choose the Save Edits As option from the Theme menu if you want to save your edits out to a new shapefile rather than changing the original shapefile. The edited version of the original theme will be written out to the new shapefile, editing will be disabled on the original theme, and the edits will not be written to the original shapefile. The new shapefile will be added to the view as a theme, the same editing environment and legend will be set up for this theme, and editing will be started on the new theme automatically. Now any edits you do will be to the new theme.

To stop editing a theme and commit your edits
Choose Stop Editing from the View's Theme menu or Stop Pegging from the Roads menu to disable editing on the theme. You will be prompted to save your edits.

Select the pegging tool

To start pegging a new road first select the pegging tool on the View toolbar. If you have not already setup Pegger you will be prompted to select a contour theme, elevation item and a contour interval.

The Pegging tool will only be available when there is an editable line theme in the view, otherwise it will be grayed out and unavailable for use.

Start a new road

To start a new road with the Pegging tool, hold down the shift key while clicking on a contour line in the view. Pegging will begin when you click on a single contour line. If PEGGER cannot determine which contour is the desired start point then the following information will be displayed:

If PEGGER cannot find any contours then the following information will be displayed:

If you are having problems then zoom in to isolate a single contour line

Add a section of road

A section of road will be pegged in when you click in the general direction you want the road to go. The current grade can be set using either the right-click popup menu, the road grade selection under the Road menu or the Pegger Toolbar.
Set the Grade
There are four ways to set the current grade in Pegger.

1. Select Road Grade under the Roads menu
2. Show the Pegger Toolbar by selecting Show Toolbar under the Roads menu
   
   
   
3. With the Pegger tool active, right-click on the view windows and select decrease grade or increase grade. The current grade will be shown in the lower left corner of the ArcView application window.
4. With the Pegger tool active, right-click on the view window and select Show/Input Grade

   

Peg a road
From any contour line there may be two or more possible points where a given grade can go. Pegger will select the point closest to where you click on the screen. The following examples help to illustrate some issues related to pegging in a road.

Unintentional Switchback
Here we are pegging in a grade at 18% going up the hill. From the end of this road there are two possible points that would satisfy the 18% grade requirement, one in the direction of the road (to the left) and the other would create a switchback (to the right).

If we click anywhere towards the left the road continues on in the same direction.

If we click to the right instead, we create a switchback on some rather steep ground. This particular switchback is not feasible due to steep grade and ground slope.

If care is not taken to choose the proper direction for the road to go a situation like to following may occur. Here the user clicked directly up the hill from the end of the road so switchback after switchback was created. This is not a feasible design!

If a section of road is added and you wish to delete it you can use the Undo command under the Edit menu or pres Ctrl+Z. You will have to start over again at the end of the road by setting the snap environment so it snaps to the end of the road then shift clicking.

Valleys
Users must also be careful crossing incised stream valleys (or draws) when using PEGGER. The image below demonstrates the problems than can be encountered when using PEGGER in steep mountainous terrain where incised stream valleys are common. The straight red segments were placed using PEGGER with a -5% grade. These segments, because of the long segment length, skip over the topography of the incised stream. At the highest point, the road is over 100 feet above the stream! In reality, this road would be built more like the curvy green segments that more closely follow the topography of the stream valleys. The road that was initially pegged at -5% grade when built would come out to something more like -3.7%. This difference in grade can be considerable depending on site specific conditions. While it may be appropriate in this situation for a more relaxed grade through the turns, if the grade were critical it would be important to look out for these circumstances.

Ridges
In addition to switchbacks and valleys, ridges must be carefully navigated in order to produce reasonable results with PEGGER. The red road was pegged at a 5% grade. Notice how the pegged road cuts right through a ridgeline. At the center of the ridge, the pegged road is over 100’ below ground! The actual road would probably be built more like the green road that extends out around the nose of the ridge. This lengthens the road and slacks the grade considerably. Care must be taken when pegging in these situations, and utilizing a dataset with a smaller contour interval may be appropriate.

Snap road to existing roads
To connect pegged in roads to existing roads use the PolyLine tool in the drawing / editing toolbar. Set the snapping environment so that the section of road that you add will snap to existing features.

For more help on ArcView’s snapping capabilities look up “snapping” in the help index or use the help tool and click on the snapping tool .

To stop editing a theme and commit your edits
Choose Stop Editing from the View's Theme menu or Stop Pegging from the Roads menu to disable editing on the theme. You will be prompted to save your edits.

Dissolve

After locating a route with Pegger there will be many segments of adjoining road that may have the same attributes. It may be desirable to join these adjacent segments into single parts to reduce data storage requirements or for additional analysis. The Dissolve function will merge adjacent features based on a common attribute. Dissolve can be used on an entire theme, or just the selected features of a theme. The output of the dissolve function is a new shapefile.

The Dissolve Lines function works only on polyline themes. Dissolve Lines will not work in an edit session.

1. To use dissolve, select Dissolve Lines under the Roads menu. In the first dialog, select the attribute that you wish to use to dissolve features on. If you would like to combine adjoining features by grade, then select the Grade field.
   
   

   

2. Second, select any additional dissolve statistics fields that you would like to be in the new dissolve shapefile. You can select multiple summary fields or none at all. Select OK to continue.
   
   
   
3. Last, select a location to save the new dissolve shapefile. By default, the new shapefile will be called “Dissolve.shp” and be stored in your current working directory.
   
   
   
4. A new dissolve theme will be added to the view. If you wish to add the new dissolved road back into the original theme, use the ArcView software editing capabilities to paste the features into the original road theme.

Merge

As the pegging tool places roads it creates many short line segments of road. There are a few reasons you may want to merge these short line segments into one large one. If you want to use the spline tool to smooth a pegged road then you must merge the segments first. If you want to survey multiple segments of a pegged road, it must first be merged into a single feature. Also, you may want to merge short segments to decrease the size of your feature attribute table.

To merge segments you must be editing the theme. Undo is available.

1. Select a continuous section of road that you would like to merge together using the selection tool .
2. Select Merge Lines under the Roads menu.

If the merge process creates undesirable results use Undo to go back.

Spline

As a final edit to your new road (or to an existing road) you may want to smooth it by using a spline function. The spline function smoothes jagged road segments by rounding pegged segment intersections. Caution must be used when splining as vertices are moved during the process. The spline function does not create true curves or follow traditional road layout techniques. It is a strictly mathematical spline function and its applicability to road engineering is questionable. It is included as a Pegger function as some have asked for it.

To spline a road segment you must be editing the theme. Undo is available.

1. Select a single segment of road to be splined. If multiple segments are to be splined then merge the segments together first.
2. Select Spline Lines under the Roads menu.
3. Enter the desired spline parameters. It may be necessary to experiment with these values in order to achieve the desired results
   
   

If the spline process creates undesirable results use Undo to go back.

Attribute Grades

If you have a road theme that has been previously pegged, the attribute grades function can be used to assign road grades to the segments. If your road theme or contour theme is large and attributing grades to the features as the road is being pegged slows the software, then attributing the grades after completing the pegging work can be more efficient.

Please note that if any changes have been made to the road theme or the contour theme after pegging the segments, or if the grade can not be determined, then the attribute grades function will assign values of 9999 to the segments.

Generally, it is more efficient to attribute road grades to the feature as they are being pegged. This can be done by running Setup Pegger under the Roads menu with the road theme selected.

Survey

Pegger can export a digital road survey to RoadEng® for detailed road design. Pegger exports digital road surveys in the Criterion Unit Survey .pol format. If there are other formats that you would like to use, please contact Luke Rogers at lwrogers@u.washington.edu and send an example file with documentation.

To survey a pegged road for export to RoadEng, either ArcView Spatial or 3D Analyst must be installed and enabled. To enable Spatial or 3D Analyst select Extensions under the File menu. In addition, a valid GRID data source or TIN data source must be in the active view and a single polyline feature selected. Pegger will only survey single polyline features. If you have a road made of many polyline segments, merge or dissolve the features into a single feature.

To use the survey function select Survey P-Line from the Roads menu. This will bring up a dialog where you can specify an 8 character survey name (PEGGER by default), the surface theme to use (either a GRID or TIN) and some survey options.

The Distance between side shots is the horizontal distance between side-shot elevation values, perpendicular to the road or on an angle bisector if the side shots are at a Turning Point (TP).

The Number of side-shots per side is the number of elevation values to collect on each side of the P-Line. If your data is stored in feet and the Distance between side-shots is 25 and the number of side-shots per side is 4, then 4 side shots will be taken at 25 foot intervals up to 100 feet away from the road on each side of the P-Line.

By default, Pegger only surveys the elevation surface at turning points. If you would like to survey the elevation surface at a regular interval that is denser than the turning points then select Densify and enter a distance between survey points.

Optionally, the survey points can be drawn in the active view as graphics. This allows you to see the points where Pegger is surveying the elevation surface and preview what will be imported into RoadEng.

By default, Pegger will name the output unit survey .pol file with the same name as the shapefile being surveyed and place it in the same directory. If you would like to specify an alternate location or name, select Browse…

Importing Survey into RoadEng
Source: Softree RoadEng® 4 Terrain Module Help File

Unit Survey data can be imported into the Terrain Module using menu File - Insert File. The Import Unit Survey Options Dialog allows you to control the format of the incoming data.

The unit survey format reads raw survey shot data. It is very useful for downloading general survey information such as radial surveys or digital data collected with a Laser Gun. The file contains foreshots, backshots and side shots.

The coordinates of each leg of the traverse are calculated based on the azimuth, inclination and distance. When a traverse contains loops, adjustments for closure are not automatic. Foreshots, backshots and multiple shots for the same leg of a traverse are averaged.

The file is in ASCII format with fields delimited by commas.

Each record contains the following fields:

For Measurement types FS, BS and SD the following fields are included in the record:

For Measurement types SR the following fields are included in the record:

Unit Survey Importing Procedure

In RoadEng Terrain Module:

1. Create a *.pol file using Pegger for ArcView Survey function.
2. From the File menu of TERRAIN select Import.
3. Select Unit Survey format.
4. Choose Options to select the formatting of the fields such as Zenith or Inclination etc.
5. Select *.pol file.

Example

TRAV1,SR,1420,2230,1311,BM1

TRAV1,BS,2,1,180:30:00,.356,120,0,0

TRAV1,FS,1,2,75:30:00,.356,120,0,0,TP2

TRAV1,SD,2,5,340:30:00,.12,67,0,0,SS2-5

TRAV1,SD,2,6,5:30:00,.12,33,0,0,SS2-6

TRAV1,FS,2,3,90:30:00,.256,60,0,0,TP3

TRAV1,FS,3,4,45:30:00,.12,93,0,0,TP4

TRAV1,SD,4,8,25:30:00,.12,85,0,0,SS4-8

TRAV1,SD,4,9,45:30:00,.12,85,0,0,SS4-9

TRAV1,SD,4,10,75:30:00,.12,85,0,0,SS4-10

Import Unit Survey Options Dialog

Source: Softree RoadEng 4 Terrain Module Help file

This dialog box is accessed through the Options button of the Import Setup Dialog, when item Unit Survey is selected. See also Importing Unit Survey Data.

• Measurements
  • Vertical
    • Enter the vertical angle format as “Elevation”
  • Horizontal
    • Enter horizontal angle format as “Azimuth (decimal deg.)”
  • Distance
    • Enter distance format as “Horizontal Distance”
• Side Slopes
  • Include
    • If selected, side shots are included otherwise they are ignored.
• Connected
  • If selected, a feature connecting the side shot to the centerline is created.
    
    

Additional Features

While all of the uses of Pegger can not be envisioned there are a few things that others have found useful in its use. Additional datasets can be used to guide in the initial placement of pegged roads. Streams, side-slope information, unstable areas, protected lands, and other GIS datasets can be very useful.

Questions, Enhancements & Bugs

Any comments or questions about Pegger can be sent to:

Luke Rogers
Research Scientist
Rural Technology Initiative
College of Forest Resources
University of Washington
Box 352100
Seattle, WA 98195-2100 U.S.A
Voice: (206) 543-7418
Email: lwrogersu.washington.edu