I have three scenes

1. the stage to build objects and test them
2. the game where everything is assembled
3. the menu

Currently I am working on the stage. You see the road sections built by extruding the standard cube. The sixth is a spare part I am experimenting with the SCA (Sensor- Actuator-Controller) setup. At the moment you can rotate a section with the mouse wheel.

Odd: you have to enter 45 degrees to get a 90 degree rotation.