Create a Paving and Milling Surface

When working with Mobile Mapping data, use the Create Paving and Milling Surface command to automatically create design models for 3D machine control systems based on existing roadway surface. This enables you to find the smoothest vertical profile (longitudinal) line while minimizing the total cut (material removal) and fill (material placement) and achieving the minimum prescribed removal depth.

Analysis conditions are displayed in graphic views and in the Project Explorer. This enables you to process point cloud data of the existing roadway surface, analyze the best-fit roadway scenario, and deliver a constructible field model to your technology-enabled machines. Additionally, you can select to display a heat map (point cloud) indicating elevation differences between the real and the estimated ideal pavement surface. Analysis results can be printed to a International Roughness Index (IRI) report that can easily be shared with others.

You can specify the minimum and maximum milling depth that extracted condition features are appropriately labeled in the Properties pane and in reports. This also enables severity labeling based on the ASTM Pavement Condition Index for both entire inspected sample units and each of the segments contained within them.

Prerequisites:

See the Subscription Plans page. For a license matrix by command, see the License page in the TBC Community. Also see View and manage licensed features.
Because the command runs on a visible point cloud, it is recommended that you classify the point cloud and use only Ground class for the analysis. This will help exclude all irrelevant classes, especially moving and parked vehicles and people (region Noise).

To Define a Surface

Click Create Paving and Milling Surface in Point Clouds > Measure. The Define Surface tab opens.
Optionally, enter a Surface Name.
Under Define Area, click in the Trajectory field, then in the Plan View select the trajectory.
Click in the Lane Lines field, then in the Plan View select the lane lines to measure.
Click in the IRI Segments field, then in the Plan View select the IRI segments to measure.
Under Designate IRI Threshold, click in the IRI Floor field and enter the necessary IRI floor. The IRI floor is measured in meters.
Under Define Milling Depth, enter the maximum and minimum Milling Depth. The depth is measured in millimeters.
Enter the Target % Surface Milled.
Note: These inputs are applied to all paving segments. See To Review Segments below to customize them for individual segments.
Under Define Additional Parameters, select the Smoothing Method from the dropdown list. The Smoothing Method enables you to choose the desired profile of the road.
- Minimal smoothing to meet IRI floor - The final surface profile is the minimum material removal to meet the IRI floor
- Linear (1st order) - The final surface profile is a linear best fit to the point cloud
- Parabolic (2nd order) - The final surface profile is a parabolic best fit to the point cloud
- Cubic (3rd order) - The final surface profile is a cubic best fit to the point cloud
- From Alignment - The final surface profile matches the selected alignment's profile
If you selected From Alignment in step 9, click in the Vertical Alignment field, then in the graphic view right-click on the selected lane line and select the alignment to measure.
The Buffer applies if there are any gaps in the scan. This extends the paved surface into those gaps. The default buffer is 0.00. Adjust this by the required amount as necessary.

To Review Segments

When the surface definition process is finished, the Review Segments tab and the Cutting Plane View pane open. Use this tab to customize individual segments, defined by each station.

In the Review Segments tab, click in the first Cross-slope (%) field. The start of each lane becomes labeled in the Plan View and the Cutting Plane View with their lane number.
Enter the Desired cross slope percentage in each Lane field. This is the amount of pavement that should be milled. The cross-slope is indicated by a red line in the Cutting Plane View. Use this view to ensure the cross-slope is correct.
Click in the Cross-slope (%) field of the second station. The end of each lane becomes labeled in the Plan View and the Cutting Plane View with their lane number.
If you have more than two stations, continue this process until you have reviewed each segment.
Use the left and right arrows to scroll between and adjust each segment.
Click the Generate tab.
Select which surfaces you want to generate.
- Initial Surface - Shows the current condition of the road
- Final Surface - Shows the paved surface
- Milled Surface - Shows the desired surface after milling
Optionally, click in the Launch IRI Report after creating surfaces to open the IRI (International Roughness Index) report pane.
Click Create.
Click in Views > 3D View to see the surface in 3D.
Note: To see just the surface, turn off the point cloud region in the Project Explorer. This gives you a view of just the crown of the surface.
If desired, Run an International Roughness Index Report.

Troubleshooting: If you cannot meet your IRI target

If one or more surface segments cannot match the parameters you set in the earlier steps without exceeding the minimum or maximum milling depth. In the warning window.

Click Yes to proceed with the process, or No to view the error and adjust the parameters.
If you click No, the Review Segments tab automatically reopens to the segment that did not meet your IRI target. You can adjust your parameters in two different ways:
1. Adjust your parameters on the Review Segments tab by editing the Cross-slope (%) that failed.
2. Adjust your parameters on the Define Surface tab by editing the IRI Floor, Milling Depth, or Smoothing Method.
In the Review Segments tab, click Create.
If desired, Run an International Roughness Index Report.