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What we did here was multiple blocks of environment with variations of assets on them and 3 variations of overall environment look (grass, town and desert).
In game, tracks is infinite and randomly generated so it's never same and it never ends. In game, goal is to get as far as possible without hitting road obstacles, while collecting fuel cans.
Game is aimed for kids from 3 - 5 years of age, so that's a reason for simplicity.
And this is how it's suppose to be used: http://ecx.images-amazon.com/images/I/6179EfjLQUL._SL1181_.jpg
Map it self is generated in straight line, and "bending" is done by shader that bends geometry from one side to another. That way we got "illusion" of bendy road, while keeping it simple for development part.
In case that above link doesn't work, here are links for video and game it self: https://www.youtube.com/watch?v=wT4JRYYPlOg
Android:
https://play.google.com/store/apps/details?id=fr.smoby.smobypilot
iOS:
https://itunes.apple.com/gb/app/smoby-pilot/id1008697390?mt=8