Nanocar racing competition and the race tracks used

In the [Nanocar race competition](https://en.m.wikipedia.org/wiki/Nanocar_Race) the molecules are raced on a gold surface. 
Is there a specific property of gold that it forms a good "racetrack"? On what criteria does it compare with other metal surfaces?




While I can't find specific justification for the surface, the first competition involved both gold and silver "racetracks."


* [Drivers gear up for world’s first nanocar race](https://doi.org/10.1038/544278a)
* [How to build and race a fast nanocar](https://doi.org/10.1038/nnano.2017.137)


The competition involves propulsion and imaging using [STM](https://en.wikipedia.org/wiki/Scanning_tunneling_microscope) so the substrate must be conductive. Gold (and silver to a lesser degree) is particularly useful, since it won't [easily oxidize](https://chemistry.stackexchange.com/questions/38996/why-is-gold-so-popular-in-nanotechnology?rq=1) and is easy to purify.


I've seen several comments about having 'tracks' in the gold surface, which suggests a well-defined crystal face with reconstruction, e.g. Au(100):


[![Au(100) surface reconstruction from Wikipedia](https://i.stack.imgur.com/foycd.jpg)](https://i.stack.imgur.com/foycd.jpg)


(Image from [Wikipedia](https://commons.wikimedia.org/wiki/File:Atomic_resolution_Au100.JPG))


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