Road Profile Control gives you manual, location-specific control over where Level AI places sawtooth high and low points. It complements the automatic Sawtooth Control settings — use it when you need to pin a high or low point at an exact location.
What is Road Profile Control?
A Road Profile Control is a drawable Roads feature (a polyline). Where the line crosses a road centreline, it forces Level AI to place a sawtooth low point or high point at that crossing when it optimises the road profile.
This is useful when you already know where a profile crest or sag needs to be — for example to direct surface runoff toward a particular inlet, to set a high point at a ridge or property boundary, or to control where roads sag for drainage.
Road Profile Control only takes effect when Saw-tooth roads on is enabled in your project's Road Settings. If saw-tooth roads are off, the control lines are ignored.
How to add a Road Profile Control
1. Add a Road Profile Control feature from the Roads feature group (it draws on the AS-ROAD-PROFILE-CONTROL layer).
2. Draw the polyline so that it crosses the road centreline at the location you want to control. Each crossing becomes a forced high or low point.
3. Set the Type attribute on the feature to choose whether the crossing is forced to a low point or a high point (see below).
4. Run Level AI. The road profile will be optimised with a sawtooth point at each crossing.
Type attribute
Type | Effect at the centreline crossing |
SAWTOOTH LOW (default) | Forces a sawtooth low point on the road profile where the line crosses the centreline. |
SAWTOOTH HIGH | Forces a sawtooth high point on the road profile where the line crosses the centreline. |
In Civil 3D each control line is drawn as a wide band, coloured and marked by its type. SAWTOOTH LOW is red, with arrows pointing in at the line: water drains to the low point. SAWTOOTH HIGH is green, with arrows pointing away from the line: water sheds from the high point. Changing the Type updates the line to match.
Checking the road design during the run
While Level AI is running, you can view the road design from the job progress card. It shows the locked low and high points from your Road Profile Controls, along with the road high and low points, the road flow and the overland flow path flow, so you can check that the controls are doing what you intended before the run finishes.
Related
Road Settings — enable saw-tooth roads and tune the automatic Sawtooth Control settings.