3D sight distance analysis

Last updated: 2022-09-16

Total video time 54:46

Warning: This workflow can be used for the 3D analysis of stopping sight distance and decision sight distance. It is not sufficient for intersection sight distance analysis. Use the Intersection sight distance - 3D analysis workflow for intersection sight distance analysis.

Standards

Sight Distances requirements: FDM 11-10-5.1, Attachments for FDM 11-10-5

dsn-chk-3d-sit-anlysis-01.mp4 3:03

Exercise files: dsn-chk-3d-sit-anlysis-begin-data-c3d22.zip

Begin with file 11701970\dsgn\check\SightDistance-51-Exist.dwg

This training will cover the creation of plan and profile sheets to display the results of a sight distance analysis. Sight lines based on the design speed are shown in the plan view and the available sight distance is shown in the profile view. The profile view elements and format are based on the example shown below.

img01

In the sight distance analysis plan and profile sheet, the y-axis of the profile is sight distance length instead of elevation.

Info:

The training covers analyzing existing conditions but may also used to analyze proposed designs.

For proposed designs, it is recommend that a Cmbn-Ex-Top surface is created (a combination of the refinement Top surface with the existing ground surface) for this analysis.

Obstruction surfaces can be evaluated with either existing or proposed conditions.

Sight distance checks

Sight distance checks can be conducted for a variety of documentation needs.

Existing Conditions based on

  • Existing alignment

  • Existing surface

Proposed Conditions based on

  • Proposed alignment

  • Combined existing surface and proposed top surface

Available sight distance for each direction of travel Example:

  • northbound/southbound
  • eastbound/westbound

Reported distances

See Visibility Check - Check Sight Distance for documentation on how the WisDOT tool reports distances.

dsn-chk-3d-sit-anlysis-02.mp4 4:05

  1. Start a new drawing from design-start.dwt template
  2. Save file as:
    1. ProjectID\dsgn\check\SightDistance-< AlignName >-Exist.dwg for existing conditions
    2. ProjectID\dsgn\check\SightDistance-< AlignName >-Prop.dwg for proposed conditions
  3. Data reference:
    1. Surface(s) to be analyzed
    2. Reference alignment
  4. X-ref files:
    1. Existing topography
    2. Pavement edgelines

Add file components

  1. WisDOT Sheets tab > Manage panel > Add Components dropdown > All Components

    1. Adding All Components will add all the WisDOT plan production elements (leader styles, dimension styles, etc.) that are not initially included in the WisDOT drawing template.
  2. Save the file

dsn-chk-3d-sit-anlysis-03.mp4 5:07

The sight distance check is a 3D analysis that will examine both the horizontal and vertical impacts. Surfaces are created to represent the obstructions along the project. Feature lines may be used to outline the obstruction.

  1. Toolspace palette > Prospector tab > Surfaces > Right-click on Exist surface > Surface Properties

    1. Surface style: EX Border
    2. OK

  2. Zoom to station 548+85 along the 51 alignment near the Wallace Road intersection.

Treeline obstruction

  1. Home tab > Create Design panel > Feature Line dropdown > Create Feature Line
    1. Name = Trees-54900-55900-R
    2. OK
    3. DRAWFEATURELINE Specify start point: Left-click to begin the treeline obstruction feature line along the right side of the 51 alignment near STA 548+85
    4. DRAWFEATURELINE Specify elevation or [Surface]:Enter to accept elevation of 0.0
    5. DRAWFEATURELINE Specify the next point or [Arc]: Left-click next location along the treeline
    6. DRAWFEATURELINE Specify grade or [Slope Elevation Difference SUrface Transition]:Enter to accept grade of 0.0
    7. DRAWFEATURELINE Specify the next point or [Arc Length Close Undo]: Left-click next location along the treeline
    8. Continue process to the end of the treeline obstruction near STA 559+00
    9. DRAWFEATURELINE Specify the next point or [Arc Length Close Undo]:Enter to complete the command

  2. Left-click to select feature line representing the treeline obstruction

    1. Feature Line contextual ribbon > Edit Elevations panel > Elevations from Surface icon
    2. Set Elevations from Surface dialog box
      1. Surface = Exist
      2. Insert intermediate grade break points = checked
      3. OK
    3. FEATUREELEVSFROMSURF Select object or [Multiple Partial]: Left-click to select feature line
    4. Enter
    5. Esc

Building obstruction

  1. Home tab > Create Design panel > Feature Line dropdown > Create Feature Line

    1. Name = Bldg-54850-R
    2. OK
    3. DRAWFEATURELINE Specify start point: Left-click to begin the treeline obstruction feature line along the right side of the 51 alignment near STA 548+74
    4. DRAWFEATURELINE Specify elevation or [Surface]:Enter to accept elevation of 0.0
    5. DRAWFEATURELINE Specify the next point or [Arc]: Left-click next location along the treeline
    6. DRAWFEATURELINE Specify grade or [Slope Elevation Difference SUrface Transition]:Enter to accept grade of 0.0
    7. DRAWFEATURELINE Specify the next point or [Arc Length Close Undo]: Left-click next location along the treeline
    8. Continue process to the end of the building obstruction
    9. DRAWFEATURELINE Specify the next point or [Arc Length Close Undo]:C to complete the command

  2. Left-click to select feature line representing the building obstruction

    1. Feature Line contextual ribbon > Edit Elevations panel > Elevations from Surface icon
    2. Set Elevations from Surface dialog box
      1. Surface = Exist
      2. Insert intermediate grade break points = not checked
        1. Note: if the feature line does not cross a void in the surface, check this option.
      3. OK
    3. FEATUREELEVSFROMSURF Select object or [Multiple Partial]: Left-click to select feature line
    4. Enter
    5. Esc
  3. Save the file

dsn-chk-3d-sit-anlysis-04.mp4 3:25

Building obstruction

  1. WisDOT Design tab > Design panel > Surfaces dropdown > Create Wall Surface

    1. DOTCREATEWALLSURFACE Select Feature Line, Survey Feature, or 3D Polyline: Left-click feature line that is the treeline.
    2. DOTCREATEWALLSURFACE Pick side to offset: Left-click inside the closed feature line.
    3. DOTCREATEWALLSURFACE Build to [Height Minimum Height Elevation]:Height
    4. DOTCREATEWALLSURFACE Enter height:20Enter
    5. DOTCREATEWALLSURFACE Enter Surface name:Bldg-54850-REnter
      1. The surface is created
    6. Esc

Treeline obstruction

  1. WisDOT Design tab > Design panel > Surfaces dropdown > Create Wall Surface

    1. DOTCREATEWALLSURFACE Select Feature Line, Survey Feature, or 3D Polyline: Left-click feature line that is the treeline.
    2. DOTCREATEWALLSURFACE Pick side to offset: Left-click to the right of the feature line.
    3. DOTCREATEWALLSURFACE Build to [Height Minimum Height Elevation]:Height
    4. DOTCREATEWALLSURFACE Enter height:30Enter
    5. DOTCREATEWALLSURFACE Enter Surface name:Trees-54900-55900-REnter
      1. The surface is created

  2. Esc

  3. View in object viewer

    1. Left-click on the Trees-54900-55900-R, Bldg-54850-R and Exist surface
    2. Contextual ribbon > General Tools panel > Object Viewer
    3. Left-click and drag to rotate and view treeline surface
    4. Close

  4. Save the file

dsn-chk-3d-sit-anlysis-05.mp4 3:45

Northbound ASD profile view

  1. Home tab > Profile & Section Views panel > Profile View dropdown > Create Profile View
    1. General
      1. Select alignment = 51
      2. Profile view name = 51-NB
      3. Profile view style = Sight Distance
    2. Station Range
      1. Automatic = selected
    3. Profile View Height
      1. User specified = selected
      2. Minimum = 0.00'
      3. Maximum = 1700'
        1. Note that for this analysis the profile height represents sight distance and not an elevation
    4. Profile Display Options
      1. Draw = uncheck all profiles
    5. Data Bands
      1. Select band set = Sight Distance
    6. Create Profile View
    7. CREATEPROFILEVIEW Select profile view origin
      1. Left-click the location where the lower left corner of the profile view will be placed

Southbound ASD profile view

  1. Home tab > Profile & Section Views panel > Profile View dropdown > Create Profile View

    1. General
      1. Select alignment = 51
      2. Profile view name = 51-SB
      3. Profile view style = Sight Distance
    2. Station Range
      1. Automatic = selected
    3. Profile View Height
      1. User specified = selected
      2. Minimum = 0.00'
      3. Maximum = 1700'
        1. Note that for this analysis the profile height represents sight distance and not an elevation
    4. Profile Display Options
      1. Draw = uncheck all profiles
    5. Data Bands
      1. Select band set = Sight Distance
    6. Create Profile View
    7. CREATEPROFILEVIEW Select profile view origin

      1. Left-click the location where the lower left corner of the profile view will be placed

Info: The profile view grid lines are located on layers E_PROF_Grid and E_PROF_GridMin and may be turned off to make it easier to see the sight distance profiles.

  1. Save the file

dsn-chk-3d-sit-anlysis-06.mp4 5:41

Perform a sight distance check that is based on a sight distance greater than what is required for the design speed. The analysis results are then used to generate a profile that will show the overall sight distance that is available. This gives the designer a better sense of the overall proximity between the available and required sight distances.

A sight distance of 1550 feet is initially used in the analysis to create the available sight distance profile. This sight distance is greater than the Decision Sight Distance Avoidance Maneuver C of 1180 feet for a design speed of 75 mph. This value may be adjusted based design project needs.

img04

Northbound ASD profile

  1. WisDOT Design tab > Analyze panel > Visibility Check dropdown > Check Sight Distance

    1. Check Sight Distance dialog box - Input

      1. Alignment = 51
      2. Start Station = 51800
      3. End Station = 60400
      4. Check Increment = 25
      5. Sight Distance = 1550
      6. Object Height = 24 in (SSD)
      7. Eye/Object Offset = 6.0 (middle of the lane)
      8. Terrain Surface = Exist
      9. Obstruction Surfaces = Bldg 54850-R, Trees 54900-55900-R

    2. Check Sight Distance dialog box - Output

      1. Create Profile = checked
        1. Name = ASD_51_NB_24IN_Exist_1550
          1. naming convention: Available Sight Distance_ < Alignment name> _ < Direction of travel > _ < Object height > _ < Exist/Prop condition > _ < Sight distance analyzed >

    3. OK

    4. Do not close the Check Sight Distance dialog box

  2. Do not close the Check Sight Distance dialog box
  3. Save the file

Southbound ASD profile

  1. The Check Sight Distance dialog box should still be open.

  2. Click the Reverse button

    1. Check Sight Distance dialog box - Input
      1. Alignment = 51
      2. Start Station = 604+00
      3. End Station = 518+00
      4. Check Increment = 25
      5. Sight Distance = 1550
      6. Object Height = 24 in (SSD)
      7. Eye/Object Offset = 6.0 (middle of the lane)
      8. Terrain Surface = Exist
      9. Obstruction Surfaces = Bldg 54850-R, Trees 54900-55900-R
    2. Check Sight Distance dialog box - Output
      1. Create Profile = checked
        1. Name = ASD_51_SB_24IN_Exist_1550
          1. naming convention: Available Sight Distance_ < Alignment name> _ < Direction of travel > _ < Object height > _ < Exist/Prop condition > _ < Sight distance analyzed >

    3. OK

Info: The profile view stationing will appear increasing in value as it does for the northbound or eastbound direction. The profile distance values have been generated in the direction of decreasing station values.

  1. Select the 51-NB profile view

    1. Profile View:51-NB contextual ribbon > Modify View panel > Profile View Properties > Profiles tab
    2. Clear/Unselect the Draw check mark for profile ASD_51_SB_24IN_Exist_1550
    3. OK
    4. Esc

  2. Select the 51-SB profile view

    1. Profile View:51-SB contextual ribbon > Modify View panel > Profile View Properties > Profiles tab
    2. Clear/Unselect the Draw check mark for profile ASD_51_NB_24IN_Exist_1550
    3. OK
    4. Esc
  3. Save the file

dsn-chk-3d-sit-anlysis-07.mp4 4:25

See Sight Distance Attachments in FDM Section 11-10 Design Controls for required standards.

Review design speeds throughout the project. Profile adjustments will need to be made at locations where the design speed changes.

  1. Home tab > Create Design panel > Profile dropdown > Profile Creation Tools

    1. CREATEPROFILELAYOUT Select profile view to create profile: Left-click to select the 51-NB profile view
    2. Create Profile - Draw New
      1. Name = SSD_51_Exist
      2. General tab > Profile style = SD Stopping Sight Distance
      3. General tab > Profile label set = _No Labels
      4. OK
    3. Profile Layout Tools - SSD_51_Exist

      1. Draw Tangents
        img06

      2. Specify start point:
        1. Transparent Command - Profile Station Elevation
        2. PSE >>Select a profile view: Left-click to select the 51-NB profile view
        3. PSE >>Specify station:51700Enter
        4. PSE >>Specify elevation:250Enter (required stopping sight distance for 35 mph design speed)
        5. PSE >>Specify station:55494Enter
        6. PSE >>Specify elevation:250Enter
        7. PSE >>Specify station:55495Enter
        8. PSE >>Specify elevation:425Enter (required stopping sight distance for 50 mph design speed)
        9. PSE >>Specify station:67520Enter
        10. PSE >>Specify elevation:425Enter
        11. Enter
        12. Esc (to end transparent command)
          1. Profile will appear in both 51-NB and 51-SB profile views since they are based on the same alignment.
      3. Esc (to end profile creation command)
    4. Close Profile Layout Tools

  2. Save the file

Info: Additional profile(s) will need to be created for Category 2 Decision Sight Distances if required. Profiles for the required SSDs and DSDs will be needed for each direction for multilane facilities.

dsn-chk-3d-sit-anlysis-08.mp4 5:32

In this training segment the Check Sight Distance tool is used to create the sight lines for a plan view based on the required sight distance for the roadway design speed. A text report may also be created for project documentation.

See Sight Distance Attachments in FDM Section 11-10 Design Controls for required standards.

Info: NOTE: A separate analysis will need to be run if there are different design speeds along the project. A separate analysis will also need to be performed if Decision Sight Distance sight lines are needed.

img07

Northbound sight lines

  1. WisDOT Design tab > Analyze panel > Visibility Check dropdown > Check Sight Distance

    1. Check Sight Distance dialog box - Input
      1. Alignment = 51
      2. Start Station = 55495
      3. End Station = 60400
      4. Check Increment = 25
      5. Sight Distance = 425
      6. Object Height = 24 in (SSD)
      7. Eye/Object Offset = 6.0 (middle of the lane)
        1. This is the distance the driver's eye and object are offset from the alignment. Positive values are always to the right of the alignment based on the direction of travel.
      8. Terrain Surface = Exist
      9. Obstruction Surfaces = Bldg 54850-R, Trees 54900-55900-R
    2. Check Sight Distance dialog box - Output
      1. Create Report = checked
        1. Location = 11701970\dsgn\check\SSD_51_NB_24IN_Exist_425.csv
          1. naming convention: Stopping Sight Distance_ < Alignment name> _ < Direction of travel > _ < Object height > _ < Exist/Prop condition > _ < Sight distance analyzed >
      2. Create Sight Lines = checked
        1. Travel Direction for Layer Assignment = NB
    3. OK
    4. Do not close the Check Sight Distance dialog box

  2. Save the file

Tip: The individual SIGHT_* layers can be turned on and off to display specific analysis results.

Southbound sight lines

  1. The Check Sight Distance dialog box should still be open.

    1. Check Sight Distance dialog box - Input
      1. Click the Reverse button
        1. Alignment = 51
        2. Start Station = 60400
        3. End Station = 55495
        4. Check Increment = 25
        5. Sight Distance = 425
        6. Object Height = 24 in (SSD)
        7. Eye/Object Offset = 6.0 (middle of the lane)
          1. This is the distance the driver's eye and object are offset from the alignment. Positive values are always to the right of the alignment based on the direction of travel.
        8. Terrain Surface = Exist
        9. Obstruction Surfaces = Bldg 54850-R, Trees 54900-55900-R
    2. Check Sight Distance dialog box - Output
      1. Create Report = checked
        1. Location = 11701970\dsgn\check\SSD_51_SB_24IN_Exist_425.csv
          1. naming convention: Stopping Sight Distance_ < Alignment name> _ < Direction of travel > _ < Object height > _ < Exist/Prop condition > _ < Sight distance analyzed >
      2. Create Sight Lines = checked
        1. Travel Direction for Layer Assignment = SB
    3. OK
    4. Close

  2. Save the file

    Tip: The individual SIGHT_* layers can be turned on and off to display specific analysis results.

Review sight line data

See Visibility Check - Check Sight Distance for created sight line and report documentation.

dsn-chk-3d-sit-anlysis-09.mp4 3:29

Plan sheets will be created for each condition, alignment and direction that is being analyzed.

  1. Output tab > Plan Production panel > Create View Frames

    1. Alignment
      1. Alignment = 51
      2. Station Range = User specified
      3. Start = 518+00
      4. End = 589+00
    2. Sheets
      1. Sheet Settings
        1. Sheet Type = Plan and Profile
      2. Template for Plan and Profile sheet
        1. Drawing template file name = C:\Wisdot\Stnd\C3D20XX\Templates\Sheets\05-PP-wdot.dwt
        2. Select a layout to create new sheets = PlanProf 1 IN 100 FT
    3. View Frame Group
      1. View Frame Group > Name = SIGHT DISTANCE ANALYSIS - NORTHBOUND
      2. View Frame > Name = Left-click on Edit View frame name... icon
        1. Name
          1. Delete and clear out default name
          2. Property fields > select Next Counter > Insert
          3. Type -NB
          4. End result should be <[Next Counter]>-NB
        2. Number style = 01, 02, 03...
        3. Starting number = 1
        4. OK
    4. Match Lines
      1. Match Line > Style = _No Display
      2. Labels > Left label style = none
      3. Labels > Right label style = none
    5. Profile Views
      1. Profile View Style > Select profile view style = Sight Distance
      2. Band Set > Select band set style = Sight Distance
    6. Create View Frames
  2. Save the file

dsn-chk-3d-sit-anlysis-10.mp4 2:24

  1. SSM

  2. Sheet Set Manager palette > Open dropdown > New Sheet Set...

    1. Begin
      1. An example sheet set = selected
      2. Next
    2. Sheet Set Example
      1. Browse to another sheet set to use as an example = selected
        1. Use file C:\Wisdot\Stnd\C3D20XX\Components\SheetSets\ProjectSheetData.dst
      2. Next
    3. Sheet Set Details
      1. Name of new sheet set = 11701970-SightDistance
      2. Store sheet set data file (.dst) here = 11701970\dsgn\check
      3. Sheet Set Properties
        1. Sheet Set Custom Properties
          1. County = ONEIDA-VILAS
          2. Highway = USH 51
          3. Project No = 1170-19-70
          4. OK
      4. Next
    4. Confirm
      1. Finish

dsn-chk-3d-sit-anlysis-11.mp4 6:53

Plan and profile sheets

  1. Output tab > Plan Production panel > Create Sheets
  2. View Frame Group and Layouts
    1. View Frame Group = SIGHT DISTANCE ANALYSIS - NORTHBOUND
    2. View frame range = All
    3. Layout Creation = All layouts in the current drawing
    4. Layout name = Left-click on Edit View frame name... icon
      1. Name
        1. Delete and clear out default name
        2. Property fields > select Next Counter > Insert
        3. Type -NB
        4. End result should be <[Next Counter]>-NB
      2. Number style = 01, 02, 03...
      3. Starting number = 1
      4. OK
    5. Choose the north arrow block to align in layouts = SheetWizard-NorthArrow

  3. Sheet Set

    1. Sheet Set = select Add to existing sheet set
      1. Left-click the ellipse icon to select sheet set = 11701970-SightDistance
    2. Sheet set storage location = 11701970\dsgn\check
    3. Sheet file name = USH51-NB

  4. Profile Views

    1. Other profile view options
      1. Get other settings from an existing profile view = selected
        1. Profile view = 51-NB
  5. Create Sheets
  6. OK
  7. CREATESHEETS Select profile view origin
    1. Left-click the location where the lower left corner of the profile view will be placed
  8. REA
    1. This may be needed to regenerate the graphics in order for the profile view grid lines to be displayed

  9. Right-click over "Layout1" tab > Delete > OK

    1. "Layout1" tab that will not be used in the file is deleted.
  10. Close the panorama

Profile view adjustments

  1. WisDOT Design tab > Design panel > Profile View menu > Profile View Elevation Range
  2. DOTPROFILEVIEWELEVRANGE Select Profile Views: Select the profile views to be adjusted
  3. Enter
  4. DOTPROFILEVIEWELEVRANGE Enter Minimum Elevation [Same]:0 Enter

  5. DOTPROFILEVIEWELEVRANGE Determine height by [New Same Elevation]:

    1. Click Elevation
      1. Enter maximum elevation greater than (minimum elevation entered):1600 Enter
  6. Save the file

dsn-chk-3d-sit-anlysis-12.mp4 6:57

  1. Set active layer to P_MISC_Text
  2. Left-click on sheet tab 01-NB
  3. WisDOT Design tab > Manage panel > Palettes ON/OFF to toggle the palette on and off.
  4. WisDOT Design tab > Analyze panel > Visibility Check dropdown > Sight Distance Palette

Required stopping sight distance profile annotation

  1. Sight Distance Tool Palette > Multileaders > CATEGORY X SIGHT DISTANCE REQUIRED, SSD FOR XX-MPH (24-IN OBJECT)

    1. EXECUTETOOL Specify leader arrowhead location or [leader Landing first Content first Options]
      1. Shift-right-click > Nearest snap 2. Left-click select a location along the required stopping sight distance profile
      2. EXECUTETOOL Specify leader landing location:
        1. Left-click select the location where the text will be located
        2. EXECUTETOOL Overwrite default text [Yes No]NoEnter
        3. Double left-click on multileader text to edit text
        4. Update text to display CATEGORY 1 SIGHT DISTANCE REQUIRED, SSD FOR 35-MPH (24-IN OBJECT)
        5. Left-click outside the text area to end the command

Available sight distance profile annotation

  1. Sight Distance Tool Palette > Multileaders > NB SIGHT DISTANCE AVAILABLE, TO 24-IN OBJECT

  2. EXECUTETOOL Specify leader arrowhead location or [leader Landing first Content first Options]

    1. Shift-right-click > Nearest snap
    2. Left-click select a location along the available sight distance profile for a 24 inch object

  3. EXECUTETOOL Specify leader landing location:

    1. Left-click select the location where the text will be located
    2. EXECUTETOOL Overwrite default text [Yes No]NoEnter
  4. Double left-click on multileader text to edit text along the available sight distance profile for a 24-inch object
    1. Update text as needed
    2. Left-click outside the text area to end the command

Sight distance profile dimension block

  1. Sight Distance Tool Palette > Blocks > SSD_PROFILE_DIM

  2. EXECUTETOOL Specify insertion point or [Basepoint Scale X Y Z Rotate]

    1. Left-click select the location where the text will be located
  3. Left-click select the dynamic block to make adjustments
    1. Left-click the blue square base point on the left side of the block to move it to the desired location
    2. Triangle grips allow the dimension lines to be adjusted
    3. Square grips near the text allow the block text to be moved
    4. Select the dropdown triangle to change the message for the dimensioned condition

      img08

See the example exhibit at the beginning of this training for additional guidance on labeling sight distance conditions.

Profile band information

  1. Double-left-click profile viewport
    1. Model space is activated within the viewport
  2. Left-click to select the profile band (lines above stationing)
  3. Profile view contextual ribbon > Modify View panel > Profile View Properties
    1. Bands tab
      1. Style = Distance Left (Available Sight Distance)
        1. Profile1 = ASD_51_NB_24IN_Exist_1550
      2. Style = Distance Right (Stopping Sight Distance)
        1. Profile1 = SSD_51_Exist
    2. OK
  4. Double-left-click outside the viewport
    1. Working in model space within the layout is deactivated

  5. Save the file

Exercise files: dsn-chk-3d-sit-anlysis-end-data-c3d22.zip