Installation

In Blender open Edit, Preferences, Get Extensions, then use Install from Disk and pick the road_kit zip.

Drawing roads

1. Open the Roads tab in the 3D viewport sidebar (N) and press Draw Road. Pick the road type first, or press Q and E while drawing.
2. Click on the ground or your terrain to place points. Clicking another road's end continues it; clicking a road's side makes a junction, or a ramp when the angle is shallow. Ctrl+Wheel raises the next points. Backspace removes a point, Enter or right click finishes the road, Esc cancels.
3. Set your terrain in the Network panel so roads sit on it and supports reach down to it. Fit Terrain to Roads grades the ground under the roads.

Editing

1. Every road is a curve: select it and edit it in Edit Mode (G to move, G Z to raise, E to extrude). The road rebuilds as you edit.
2. With a road selected, the Road panel shows its type and all of its settings: lanes and markings, surface and colors, curbs and sidewalks, median, elevation and bridges, lights and extras. Copy to Selected Roads copies them to other roads.
3. Select a junction's circle handle to choose its control (signals, stop, yield, roundabout), crosswalks and corner radius.
4. Weather and Look sets rain, snow, dirt, wear and lamps for the whole network; Set Up Sky and Sun adds a matching sky. Turn on Real Lights for night renders.
5. Make Static keeps the meshes as ordinary objects.

Use Rendered view (EEVEE or Cycles) to see wet reflections and lights. Add Demo City in the Roads tab shows every feature.