The roads use basic shapes that easily snap together. There are 2 intersection types(4 way, T). This allows for easy flat grid building.
Because it is highly grid based, BSP brushes can easily be used to build the lots.
**We highly recommend using these assets with in game splines, or to open the FBXs provided in a 3rd party 3d software (maya, blender) and use the assets to build your levels as larger chunks and export those back into UE4.