Primary / minimal pavement addition could be just textured tiles, no functionality, can be destroyed and can be walked on. There could be some different colors / textures. Maybe wood, cobblestone, stone slabs, metal slabs, maybe some colored ones, etc. ... Just to make roads and/or mark areas at minimum.
Example ideas that player could do if there would be pavement added : Marking different factory areas with different colors, making parking and landing areas, planning buildings / placeholders, more options for bored engineer to make art!, ...
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Secondary pavement addition (maybe later version of game) could be adding somekind hp bonus for turrets etc. that have been build over stone/metal pavement. Maybe moving speed bonus etc. (for robots, car and/or player) when moving over pavement.