﻿ Smart Curves

# Knowledge Base

## Smart Curves

Updated May 31, 2024

• Softree Optimal

Download the example files used in this tutorial: Hart Rd Optimal Smart Curves
Extract / unzip prior to beginning the tutorial.

Smart Curves allows you to simplify vertical curves. This is performed using two different actions; Merging Curves and Vertical IP Reduction.

Merging Curves

In a vertical alignment, adjacent curves with similar K values can be merged together to form a singular curve. This routine will merge curves that follow two rules:

1. Their intercurve station distance are within the user-supplied tolerance, expressed in project units.
2. They are relatively similar in K value, expressed in percent (%) change.

Note: Only curves of the same kind (crest or sag) will be considered. Adjacent curves with K values of opposing sign will be ignored.

Vertical IP Reduction

Location represents vertical curves as a polyline, connecting the start station to end station with VIPs in between. The VIP reduction component uses the Ramer-Douglas-Peucker algorithm to simplify the curve while preserving the general geometry of the polyline, up to a tolerance. This reduction tolerance represents the largest deviation that the simplified polyline will have from the original, expressed in project units.

This first example will look at the Smart Curves tool. We will use the same files (back to back curves with no tangents) used in the previous example, but this time we will run the Optimizer with Smart Curves tool turned on.

1. Open the Location Module  application.

1. File button | Open. Select Hart Rd optimal.dsnx. Press Open.

2. Maximize  the Profile window, ensure the Alignment Properties panel is visible

3. Press  to visualize the vertical profiles. Select Trial 1 and give a look at the profile.

4. Zoom in at the start of the alignment.
Figure 1: Consecutive point in Trial 1 alignment

Note: Although Trial 1 is an alignment with applied curves, there are too many consecutive points that would complicate the project during the construction phase.​​​​​​

5. Make a copy of Trial 1 and modify the description:

• In the Project Explorer list, select Trial 1. Right-click then press the Add Vertical...button.

• Change the Description to “K=30 with Smart Curves”.

• Select the Standards tab and ensure the Curvature (minimum K) is set to 30 for Sag and Crest.

Figure 2: Options, Standards tab with min. Curvature K defined.

• Press OK to close the modified options (nothing else should be changed).

• Check the Re-cost box when prompted by the Recalcule Range dialog.

1. Create an optimized vertical profile:

• Right click on Trial 2 alignment and select Vertical Optimization....

• Turn Smart Curves checkbox On.

• Press Process. Press OK to close the Log dialog.

Now, we will compare Trial 1 and Trial 2.

1. Compare Trial 2 and Trial 1:

• Trial 2 should still be selected. If not, left-click on Trial 2 to set it to current.

• Right-Click on Trial 1 and Re-Cost if necessary.

• Select Compare to Current button. Use the drop-down lists to set Horizontal Alignment 1 and V-Trial 1 alignments.

These solutions are very similar; the total cost difference is just below 1% and the selected Trial 2 profile (magenta) is almost coincident with the initial Trial 1 profile (thin blue line).

Figure 3: Comparing the differences between alignments generated without and with Smart Curves.

Note:  Compared to Trial 1 (Initial), Trial 2 profile (Smart Curves one) has increased the total cost by \$2430. However, you can notice that all the existing VIP's have transitioned into a smoother vertical profile, which will enhance the constructability of the project.

1. Now, we will show the graph of the start of the v-alignment with the same scale for both cases. This will aid in better understanding the efficacy of this tool.

Figure 4: Graph of the difference between the Initial (Trial 1) and the Smart Curves (Trial 2) alignment.

2. File  | Close. Do not save changes.