Side objects and Road Types can be used across projects by exporting them to a unity package and importing this package in the other project. This section demonstrates how this is done for side objects. The same steps can be followed for road types.
Open the Side Object Manager (2nd tab from the right) and click the Export Side Objects button
Select the Side Objects you want to export and click the Export button at the bottom.
This will generate a new prefab with side object info. You will be asked to set a location where you want to save it. Make sure to chose a location inside the assets folder.
Afterwards you will be asked where to save the unity package, this can be any location. This package will include all assets used by the exported side objects. The initially saved prefab is part of the package and automatically removed from this project after the package is created. We will use this prefab in the other project to import the side objects in the system.
The first step is to import the package that includes the side object data and required assets. This the package we created above. Importing the package works just like any other unity package: Top Menu > Assets > Import Package > Custom Package. Select the package exported above, the package will be imported in the open project.
Open a scene with a Road Network already part of the scene. In the Side Object Manager tab click the Import Side Objects button. The side object import window appears. This is an empty window asking to drop the source prefab on the canvas.
Browse in the assets folder to the location of the source prefab, the prefab we saved during the export steps above. Drag/drop this prefab in the Import window. The side objects will appear, you can select which to import.
Click "Import". The selected side objects will be added to the Side Object Manager and are ready to be used in the scene.