Extend roads and connect transition curves
Extend tools continue from the end of an existing road. Transition-curve connection joins two roads more smoothly, avoiding abrupt direction or curvature changes.
- Select the road you want to extend.
- Choose extend straight or extend arc.
- Move the cursor to the new end point and read the preview line from the current road end.
- Left-click when the preview is valid.
For transition-curve connection, select the first road, choose the connection tool, move the cursor over the target road, then confirm the valid preview.
| Failure | Meaning | What to try |
|---|---|---|
| Cannot compute transition curve | Angle, distance, or curvature does not fit the connection | Move roads, increase connection length, or use straight/arc segments |
| Length is not enough | The connecting straight, circular, or transition segment is too short | Leave more space between roads |
| Cannot connect this road | The target end is unavailable or already occupied | Use another end or remove the existing connection |