Streets are very important to the infrastructure in Unknown Horizons, therefore building them should be as easy and intuitive as possible.
The time a good needs to be delivered from building A to building B is measured by the length of the shortest road connecting those buildings.
If the player decides to build a road, he has to click with the left mouse button on the point where he wants the street to start first and then hold the button until the process is finished. If the button is released, the road planning is immediately considered done. He then moves the pointer to the place where it shall end. If these two points are not in a direct line, there are two possibilities how the road can go: Either clockwise or counterclockwise (see the picture). The user can easily switch between those two options by pressing the right mouse button. The setting the player last used is saved as initial option when he builds the next street. If there is no such setting saved, the behaviour defaults to counterclockwise.
For every kind of street there has to be a set of images featuring 8 directions with turns, crossroads and possibly gateways for buildings.
The most likely streets are (contingently build from different materials?!):
The 8 directions are (clockwise):
This feature is already implemented to a certain degree.