Well, I built it on a monitor that had an aspect ratio of 16x10. It eventually died and now I'm working on a 2048x1152 monitor with an aspect ratio of 16x9.
In the end, your resolution doesn't really matter. It depends on what you like: do you like the hi-res look of the road combined with the lo-res pixel art, choose a high resolution. Otherwise I would suggest you scale it down.
I'm about to add some aspect ratio options too. 😉